Transfer number to new phone

I am a member of xfinity mobile and I just got a new phone. My last phone was connected to xfinity and I want to transfer my number to my new phone. I moved the sim to my new phone but it seems like it’s not registering. I do have the app but I can’t find anywhere in the app that is helping to solving this problem. Do I need to go into an xfinity store for them to fix it or is there a way for me to transfer my number through the app that I’m not finding?