I cannot find any piece of information about it in the AliExpress help pages or anywhere else online. Assume you use your real name in name section. There is no alias possibility. One option is then use fake name in name section of the profile.
Now, they use the strategy to show user's first digit in first name and last name like
M*** M. where first name
Masi and lastname
They do not have any contact form to contact them so I cannot get this further. Now, I use a nick name in profile's name field, but then, keep correct details in shipping address when shopping.
How can you change the public profile name in AliExpress?