You can find your paystubs, W2, an employment verification letter, and can update your direct deposit on the UCPath website. After you log in, go to Employee Actions then Income and Taxes.
https://ucpath.universityofcalifornia.edu/home
For paystubs prior to April 2020, please login to At Your Service Online: https://atyourserviceonline.ucop.edu/ayso/ to retrieve these.