Hello,
Since you didn’t subscribe add-on subscription, the integrated Offer Management App isn’t available at all. By Integrated offer management app, I mean the app accessed by clicking this button:

In your case, offer is tracked manually, just setting offer status Accepted/Rejected.

So what are you trying to skip here? Are you just trying to delete the offer stage here? If so, then in my understanding that’s not possible.

Regards,