"How to use OAuth2 access token..." <- Hi Adarsh, to create an OAuth2 access token in Koha, you have to do the following steps: 1. Enable the system preference: RESTOAuth2ClientCredentials. 2. Go to the patron you want to create an OAuth-Token for or log in with this account on the intranet. 3. On /cgi-bin/koha/members/moremember.pl?borrowernumber=, click on "More" -> "Manage API-Keys" -> "Generate a new client id/key pair," and add a description for the API keys. BTW: There is also a public biblio endpoint at /api/v1/public/biblios/ where you dont have to authenticate via API Tokens. For some use-cases this is also really helpful :)