The steps to use your surname in your WeChat avatar are as follows:
Step 1: First open "WeChat" on your phone, and then enter the "Mini Program". Then search for "surname picture" in the mini program, and then click to enter the mini program to start making a surname avatar.
Step 2: After opening the surname map applet, you only need to enter your "surname", such as "Liu", and then "click to generate".