Hello!
These cactus (all 3 kinds of them) love to be root bound. If they aren’t they tend to not like to bloom.
I would suggest giving them some fertilizer of some sort. Natural or store bought. Sometimes that helps get blooms.
Although sometimes they are just temperamental and it takes them a few years to decide to share their beauty again. Lighting and temperatures can also play a part in if they bloom or not. There’s information out there about putting them in a dark room for a specific amount of time to get them back to blooming. I’ve never personally done it but I have read online about it.
Hope you get it blooming again soon!