How to use OAuth option in SAP PO 7.5

Hello Experts,

I need help to configure below scenario in SAP PO 7.5 system.
I want to establish connection with AWS server based API's using REST adapter provided by SAP.

This is 2 step method

1 - Call token URL by giving specific(fix) header
this URL will return token number and expiry time like below

{

"access_token": "eyJraWQiOiJpen..........",
"expires_in": 3600,
"token_type": "Bearer"

}

2 -Call API to post main JSON payload with access token as header received from token API.

I have currently configured REST receiver channel as below.

My question is how caching worked and how to use token which is received by token API.

Regards,
Chetan Risbud