What is the way to send international long-distance short messages?

International long-distance short message sending method: 00- country code (the other country)-called user number description: Description: No international long-distance function is required.

For example, send a short message to an American user in mainland China and enter "00 1+ user's mobile phone number" as the receiving number. (Note: No "0" can be added before the user's mobile phone number)