Can not authenticate API (Authentication mode: JWT) without Policy

In my context, I am using Tyk Cloud Gateway to authenticate incoming request with Authentication mode is JWT and Signing Method is RSA Public Key.

However, I do not associate any policy to this API Endpoint since I have no permission to config the Token Issuer to add custom Claim for Policy Field Name (default: pol) while signing the token.

Although the Token is verified successfully, I always receive the following error message from Tyk:
{
** “error”: “Key not authorized: no matching policy found”**
}

If I change the Signing Method to HMAC (Shared), it works properly.

So we have no way to authenticate the incoming requests using JWT with RSA Public Key ?
For more information, please take a look at the bellow API Definition & Postman Request Payload:
Postman Request Payload
HTTP GET https://nat-bet.cloud.tyk.io/jwt-test
Headers:
Authorization: Bearer eyJhbGciOiJSUzI1NiIsInR5cCI6IkpXVCJ9.eyJpc3MiOiJodHRwczovL2p3dC1pZHAuZXhhbXBsZS5jb20iLCJzdWIiOiJtYWlsdG86bWlrZUBleGFtcGxlLmNvbSIsIm5iZiI6MTUzOTA1MjM4MSwiZXhwIjoxNTcwNTg4MzgxLCJpYXQiOjE1MzkwNTIzODEsImp0aSI6ImlkMTIzNDU2IiwidHlwIjoiaHR0cHM6Ly9leGFtcGxlLmNvbS9yZWdpc3RlciJ9.2ZkNrkDWCLe6moCdepH7jLEKqNMl6hCzcBQTie9J30sIOkRMJ1VGWLnFY5dTktTkC4Bwzi-X6VRIvPijACRVW4UtKc-zGeLmq2S7BfYCZjipA-3j8uP90syG8Au7fTwCXZX2FrYBP-uYQpCZNFJgJnP_GaU2TmXgvMws-aLOiAn8CS5W8WwnAy6lVx-kA5Tkm2atQWZyylI9xFzgrd4fumJh2r7oxYOy-aNo62LN0YUn3f3y0RmjAm4DMGZDrVM70KrbModZBuJGGYyfI-q05wEbgkvKob-Wtc-mR25GGsbAechRRzH20QwLRMgf4d2skN878_pdLIdM3m1Js3UHYw

API Definition
{
“id”: “5ad4824006b7760001da9aac”,
“name”: “jwt-test”,
“slug”: “jwt-test”,
“api_id”: “24279d44721d44f7561c275ed83a7914”,
“org_id”: “5acb1f6df3387c0001583cff”,
“use_keyless”: false,
“use_oauth2”: false,
“use_openid”: false,
“openid_options”: {
“providers”: [],
“segregate_by_client”: false
},
“oauth_meta”: {
“allowed_access_types”: [],
“allowed_authorize_types”: [],
“auth_login_redirect”: “”
},
“auth”: {
“use_param”: false,
“param_name”: “”,
“use_cookie”: false,
“cookie_name”: “”,
“auth_header_name”: “Authorization”,
“use_certificate”: false
},
“use_basic_auth”: false,
“basic_auth”: {
“disable_caching”: false,
“cache_ttl”: 0
},
“use_mutual_tls_auth”: false,
“client_certificates”: [],
“upstream_certificates”: {},
“pinned_public_keys”: {},
“enable_jwt”: true,
“use_standard_auth”: false,
“enable_coprocess_auth”: false,
“jwt_signing_method”: “rsa”,
“jwt_source”: “LS0tLS1CRUdJTiBQVUJMSUMgS0VZLS0tLS0KTUlJQklqQU5CZ2txaGtpRzl3MEJBUUVGQUFPQ0FROEFNSUlCQ2dLQ0FRRUEzM1RxcUxSM2VlVW1EdEhTODlxRgozcDRNUDdXZnF0MlpqajNsWmpMampDR0R2d3I5Y0pObE5EaXVLYm9PRGdVaVQ0WmRQV2JPaU1BZkRjRHpsT3hBCjA0RERuRUZHQWYra0RRaU5TZTJadHFDN2JuSWM4K0tTRy9xT0dRSVZhYXk0VWNyNm92RGt5a081SHhuN09VN3MKSnA5VFA5SDBKSDh6TVFBNll6aWpZSDlMc3VwVGVyclkzVTZ6eWloVkVEWFhPdjA4dkJIazUwQk1GSmJFOWl3Rgp3bnhDc1U1K1VaVVpZdzg3VXUwbjRMUEZTOUJUOHRVSXZBZm5SWElFV0NoYTNLYkZXbWRaUVpseXJGdzBidVVFCmYwWU4zL1EwYXVCa2RiRFIvRVMyUGJnS1RKZGtqYy9yRWVNMFR4dk9VZjdIdVVOT2hydEFWRU4xRDV1dXhFMVcKU3dJREFRQUIKLS0tLS1FTkQgUFVCTElDIEtFWS0tLS0t”,
“jwt_identity_base_field”: “”,
“jwt_client_base_field”: “”,
“jwt_policy_field_name”: “”,
“jwt_disable_issued_at_validation”: false,
“jwt_disable_expires_at_validation”: false,
“jwt_disable_not_before_validation”: false,
“jwt_skip_kid”: false,
“notifications”: {
“shared_secret”: “”,
“oauth_on_keychange_url”: “”
},
“enable_signature_checking”: false,
“hmac_allowed_clock_skew”: -1,
“base_identity_provided_by”: “”,
“definition”: {
“location”: “header”,
“key”: “x-api-version”,
“strip_path”: false
},
“version_data”: {
“not_versioned”: true,
“default_version”: “”,
“versions”: {
“Default”: {
“name”: “Default”,
“expires”: “”,
“paths”: {
“ignored”: [],
“white_list”: [],
“black_list”: []
},
“use_extended_paths”: true,
“extended_paths”: {},
“global_headers”: {},
“global_headers_remove”: [],
“global_size_limit”: 0,
“override_target”: “”
}
}
},
“uptime_tests”: {
“check_list”: [],
“config”: {
“expire_utime_after”: 0,
“service_discovery”: {
“use_discovery_service”: false,
“query_endpoint”: “”,
“use_nested_query”: false,
“parent_data_path”: “”,
“data_path”: “”,
“port_data_path”: “”,
“target_path”: “”,
“use_target_list”: false,
“cache_timeout”: 60,
“endpoint_returns_list”: false
},
“recheck_wait”: 0
}
},
“proxy”: {
“preserve_host_header”: false,
“listen_path”: “/24279d44721d44f7561c275ed83a7914/”,
“target_url”: “http://httpbin.org/”,
“strip_listen_path”: true,
“enable_load_balancing”: false,
“target_list”: [],
“check_host_against_uptime_tests”: false,
“service_discovery”: {
“use_discovery_service”: false,
“query_endpoint”: “”,
“use_nested_query”: false,
“parent_data_path”: “”,
“data_path”: “”,
“port_data_path”: “”,
“target_path”: “”,
“use_target_list”: false,
“cache_timeout”: 0,
“endpoint_returns_list”: false
},
“transport”: {
“ssl_ciphers”: [],
“ssl_min_version”: 0,
“proxy_url”: “”
}
},
“disable_rate_limit”: false,
“disable_quota”: false,
“custom_middleware”: {
“pre”: [],
“post”: [],
“post_key_auth”: [],
“auth_check”: {
“name”: “”,
“path”: “”,
“require_session”: false
},
“response”: [],
“driver”: “”,
“id_extractor”: {
“extract_from”: “”,
“extract_with”: “”,
“extractor_config”: {}
}
},
“custom_middleware_bundle”: “”,
“cache_options”: {
“cache_timeout”: 60,
“enable_cache”: true,
“cache_all_safe_requests”: false,
“cache_response_codes”: [],
“enable_upstream_cache_control”: false,
“cache_control_ttl_header”: “”
},
“session_lifetime”: 0,
“active”: true,
“auth_provider”: {
“name”: “”,
“storage_engine”: “”,
“meta”: {}
},
“session_provider”: {
“name”: “”,
“storage_engine”: “”,
“meta”: {}
},
“event_handlers”: {
“events”: {}
},
“enable_batch_request_support”: false,
“enable_ip_whitelisting”: false,
“allowed_ips”: [],
“enable_ip_blacklisting”: false,
“blacklisted_ips”: [],
“dont_set_quota_on_create”: false,
“expire_analytics_after”: 0,
“response_processors”: [],
“CORS”: {
“enable”: false,
“allowed_origins”: [],
“allowed_methods”: [],
“allowed_headers”: [],
“exposed_headers”: [],
“allow_credentials”: false,
“max_age”: 24,
“options_passthrough”: false,
“debug”: false
},
“domain”: “”,
“do_not_track”: false,
“tags”: [],
“enable_context_vars”: false,
“config_data”: {},
“tag_headers”: [],
“global_rate_limit”: {
“rate”: 0,
“per”: 0
},
“strip_auth_data”: false
}

Any help is much appreciated.