convert2rhel imposible from centos 8

Hello i have a problem with convert2rhel, i try to do it with convert2rhel --username=mail@server.com --password=mypassword and without username and password he ask me later.
The problem is:
Attempt 2 of 3: Registering the system using subscription-manager ...
'ascii' codec can't encode character '\xe1' in position 7: ordinal not in range(128)
System registration failed with return code = 70
Trying again - provide username and password.
Building subscription-manager command ...
... activation key not found, username and password required
Username:

Password:

If i do it with subscription-manager then works. But when i run convert2rhel he delete the subscription and i have to write again with the same problem. Thanks for your help.