The prefix of Shopee login name can be the mobile phone number, email address, or Shopee user ID when registering. Because in the registration process of Shopee, these three methods can be used as the prefix of the login name. So you can fill in the prefix according to the method you used when registering. However, it should be noted that if you use a mobile phone number or email address as a prefix, then you need to make sure that this information is accurate, otherwise it may cause login failure or other problems.