Hi @YadhuS ,
The documentation for the given REST API endpoint is indeed confusing since, even if it is providing the link to the right documentation page, it is not mentioning that you need to actually follow a different procedure than the one to create Oauth2 apps:
For more details on integrating Jira Software Cloud with on-premises tools using OAuth 2.0 credentials, see Integrating Jira Software Cloud with on-premises tools.
Indeed, the OAuth 2.0 credentials (client ID and secret) to authenticate calls against the below endpoints have to be created in Jira by following the steps provided in the linked documentation page and not in the developer console:
For further details and instructions please review:
I hope this clarifies.
Cheers,
Dario