Hi Girish,
I would strongly reccomend you to update your app and jump to the latest LTS version for Mendix 9 as your version is not properly maintained anymore. (You can find more information about the different Mendix Versions here).
Is there a specific reason why you cant jump to a higher version? Else that would be the easiest fix.
With best regards,
Levin
Hi Girish,
you can use oauth for authenticating via token by any of below modules
Mendix Marketplace - OAuth 2 Authorization for APIs - example
OIDC SSO module indeed allows your API implementation to validate the OAuth Access Token / bearer token.
This works both for Access Tokens that were obtained via SSO Authorisation Code grant (SSO) or through Client Credential grant (i.e. client app acting on it's own behalf).