OK, then i find reply for my question on link https://support.mozilla.org/en-US/kb/openpgp-thunderbird-howto-and-faq Quote: "Enigmail used to offer searching on non-verifying keyservers. At this time Thunderbird doesn't offer that, because of the various issues that were detected with those keyservers in the recent past. If you need to obtain a key from a keyserver that isn't currently supported by Thunderbird 78, then you must use other software to obtain it, then save it to a file, then you can use OpenPGP Key Manager to import the public key file" It is a pity that this option is not available.