Never. Pullups, dips, deadlifts, squats = for life!
To get back into any of these start with kettlebell swings, as your grip strength returns, you will find pullups easier.
I like to do 10 pullups, 9 chinups, 8 pullups, 7 chinups and so forth until I get to 1 every other day no matter what. I'm 43 in 1 month.
Read this:
https://foreverfitscience.com/exerci...body-strength/