Administrative section check the checkbox “Api Only User”.

API Only specifies that the user can only log in through the API. This prevents the user from being used for any purpose other than integration scenarios.

User cannot login through the UI. It can only create a session through the API.

User doesn’t have the ability to reset their security token.

Check this for additional information – https://help.salesforce.com/articleView?id=000331470&type=1&mode=1