OAuth token without cilent_id & client_secret

Hello Team,

As from Gitlab 13.9 the access token is not generated until and unless we provide client_id & client_secret in oauth api, previously with grant_type and username the token was able to generate. Can you suggest something on how to skip this action from GitLab 13.9 and above as we have a self managed omniauth GitLab free-tier created at our end and which require this access token without creation of client_id & client_secret. As those creation can be delete by anyone who is admin for that GitLab.

Thanks & Regards,
Yashraj Choudhary