TIB setup with external OAuth server to grant access to TYK API

Hi All,

I’m very new to tyk platform and got stuck as I got urgent requirement from my client, I want an help.
What I want to achieve?
I have my own OAuth server of grant_type=password. I want to authenticate users using this and grant the access to tyk API Gateway to access target API. Basically want to setup TIB. I didn’t find the relevant support in the web. Could anyone please help with the guide or some blog.
Greatly appreciate the help!