For all mail letters from 1s Bitrix, the same letter header is used. Where to set it up?

Question

1C-Bitrix

Made the integration of 1s-bitrix and b24. After that, something happened with sending emails. All email templates work, but the email header is now always "Bitrix 24".

What could be the problem? Ideally, I would like the title of the letter to be taken from the settings of the mail template, but in principle, even replacing the existing title with another one will do.