How to manage Job Offer after Move To HR

Hi Team!
I'm writing you to receive support in order to manage as well as possible a client request.
The client wants to manage the Job Offer after the preboarding is triggered, I mean after the Move to HR, cause of the candidate receives the Job Offer after passing a series of examinations.
The examinations are handled by using tasks in preboarding steps, so they want to create a Job Offer and, after acceptance, to continue the preboarding, so other tasks.

Do you have any suggestion to take in action?
Thanks in advance
Tommaso