Error in phone number verification

I can’t create a new account from all my devices I have due to the error when verifying my phone number. It says your code cannot include your phone number or something. I entered exactly the same 6-digit number as the code I received and tried several times, but it failed. By the way, I had to create my account because I need the one can be used in US although I already have Japanese one. Isn’t it possible to have two accounts?