The trigger service itself never parses tokens, so the user/claim distinction makes no difference to its main code.

As with the auth middleware #12830, the main area of user token porting interest is in the tests themselves. Specifically:

• SandboxFixture in TriggerServiceFixture.scala passes a claim token to the ledger client, which is then used for direct interaction with the participant (the trigger service itself doesn't see this token in the tests): use user token for trigger service sandbox test fixture #13077
• trigger.AuthMiddlewareFixture sets up the oauth2 test server to return claim tokens; with port auth middleware "test client" for user tokens #12929 we can return user tokens instead and see what happens: enable oauth2-test's user tokens in trigger service tests #12994