Hello, I made a backup in iTunes, but I don't know the password of my backup. help

See Disable iOS backup encryption - Apple Community. In particular:

If you have forgotten the password, or were not aware that encryption had been enabled, consider that it might be any computer, Apple ID, Wi-Fi password or device PIN that you've used in the past, working from the assumption that you might have reused a common password that you were using when encryption was first activated. See About encrypted backups on your iPhone, iPad, or iPod touch - Apple Support for details.

tt2

You’ll need your password, there is no way to reset it or to get help for something only you know.