Kid over 18, Can we add name as co owner during closing of preconstruction condo

Hi All,
We booked a condo in 2018 in GTA . its interm occupancy is coming in summer 2022 & closing should occur soon later. When we book the condo. It was in our couple name . Our child was minor in 2018. But now the age is more than 18. My question is can we add child’s name during closing. Did anyone experience this situation . What are the issues we need to take care . I want to do joint tenancy

I am not worried about his first-time buyer loss of benefits. Also I understand the mortgage will come on his name too. That’s fine


Thanks in advance

regards