you’ll have to look at each UC to see their policies, but the program exists. Here are 2 sample links
http://www.sbcc.edu/transferacademy/cross_enrollment.php
https://students.ucsd.edu/academics/enroll/undergraduate-enrollment/community-college-csu-students.html
note that these will be real UC classes and will count towards your UC gpa. Although I haven’t done this, I imagine to get credit you just list the UC class(es) you’ve taken on your app just as you would for classes from any college, and send them an official transcript when admitted.
also be sure to check into any unit cap issues. The UCs add all UC units on to the total you’ve taken at a CC, so you don’t want to end up with too many units to transfer