not all of my apps tranaferred from iphone 12 pro to iphone 15

I must have touched something wrong when I initially tried to pair my phones together to get all my info from iPhone 12 Pro to iPhone 15 today. I had to resort to an apple representative. I THOUGHT he took care of it all - it took an hour - but when I went to access my apps on the new phone (the 15) most of them weren’t there. Any suggestions?