Merchants can setup a PayPal Business account below (choose Website Payments Standard as the account type):
For Singapore merchants: https://www.paypal.com/sg/cgi-bin/webscr?cmd=_biz-signup-flow
For Hong Kong merchants: https://www.paypal.com/hk/cgi-bin/webscr?cmd=_biz-signup-flow
For Malaysia merchants: https://www.paypal.com/my/cgi-bin/webscr?cmd=_biz-signup-flow
For Vietnam merchants: https://www.paypal.com/vn/cgi-bin/webscr?cmd=_biz-signup-flow
Once you go into one of the websites above, follow the instructions to setup your PayPal account. Once your business account has been setup, you will need to verify your email address.
You have then completed the PayPal account setup!