Good day, Anton!
Uncommented the line:
The situation is as follow:
All Russian characters began to be interpreted correctly.
But at the same time, all characters (Latin, Russian are interpreted as non-Unicode characters. The same text is 82 characters, one consists of Latin, the other is Cyrillic (Russian), both are treated as 1 SMS. Although in the second case, instead of 1, there should have been 2 SMSs. And another such case: if after 82 Latin characters Cyril (Russian) is also indicated, that is, mixed Latin and Cyrillic characters are also treated as the same.
P.S. Unicode = 1 not specified in URL API
Respectfully,
Jamshid Tursunov