Project Resource assignment workflow auto approval

Hello Experts, As part of project resource assignment, we have a requirement to auto approve the new assignments. So in sort if any new resource is added by PM , he should be directly able to approve the same without firing the workflow. I thought it was possible so i set up the status to not use the PAWFAAP workflow.

Starting status: working

Next Allowable status: Approved  without using the workflow.

I setup the resource authority also for the PM and was able to see approve button but it didnt work. And when i submit the resource for approval, it will start the workflow. I am not sure how and where this workflow is firing. I would request expert to please suggest how can i auto approve the resources without using the workflow.