Claim Time Machine backups on new computer after choosing the “later” choice on migration assistant.

While running migration assistant, I selected “later” when asked to claim old backups for the new machine or start new. It seemed like a good idea at the time. Now I have checked the transfer etc and am ready for backups. How do I claim the old backups for the new machine? I don’t think I can run migration assistant again without starting over ? I really don’t want to wait on that again. I’m running Ventura. No choice below for it.