Hi Andrea,
Welcome back to the community. I think it is quite an interesting use case and I remember there was a very interesting demo presented during developer days 2024 which you may try to watch and make use of the similar logic.
You may need to tweak your logic a little bit and probably have multiple empty roles setup initially without approval and then once the user consents then trigger the request for the relevant actual role via workflow.
If user does not give the consent then you may remove this empty role from workflow for the user. But i think it might work provided the number of such roles are not too many.
I hope this helps, if any issues, please let us know.
Thank You.
Regards
Vikas.