It is necessary to enter in the database the password from the account in an encrypted form. It looks something like this: òøÜÜØòjl. When I send mysqli_query with this parameter from my script, it simply does not execute, although if I send it from phpMyAdmin, then everything works. By the way, if you send characters of the type "a, b, c ..." in the request - there is no problem.
mysqli_query($link, "INSERT INTO `users` (`Nickname`, `Password`) VALUES ('qwerty', 'òøÜâÜØÚòjl')");