Put your surname/family name in last name field.
So if your name is Lau Tak Wah,
Firstname: Tak Wah
Lastname: Lau

If your name is Andy Lau Tak Wah,
Firstname: Andy Tak Wah
Lastname: Lau

Some forms can put middle name, if got you can do,
Firstname: Andy
Middlename: Tak Wah
Lastname: Lau

This post has been edited by silic0sis: Aug 17 2017, 12:15 AM