Use the "Home Sale Worksheet".

If it was still a rental in 2018, you can 'link' the Asset Entry Worksheet to the Home Sale Worksheet (it is in the disposition section of the Asset Entry Worksheet).

However, you said it was a personal residence in 2018?  Did the client move back into the home?  Did he use it as his Principal Residence in 2018?  Using it as his Principal Residence would trigger the Nonqualified Use rules.