Edit and publish existing add-ons

Hi all.
We use add-on “Check domain” , but it only supports up to version 52.* of Thunderbird.
We found solution. Need to change value of “maxVersion” in file install.rdf.
We want use published version, but we could not contact with developer of that add-on to verify and publish it.
Is there a way to fix this issue and publish it?

This one?

If you open the .xpi file using your favorite Zip utility and look in license.txt, there is an email address for the author.

If the author does not respond, note that the extension was released under the Mozilla Public License 1.1, an open source license, so you have the right to modify and publish a revised version as long as you follow the steps in section 3 of the license.

Note: You would need to publish under a new listing on the Add-ons site if the author doesn’t update the original listing.

Thank you for your answer. Is it really necessary to publish your version for this? Because we do not change anything in the code, we only need to change value of “maxVersion” in file install.rdf.
And in my opinion it is not ethical, to change only one value and to publish on its own behalf. If I misunderstand something from your answer, please write in detail, what we should do in this situation.

Modified versions would need to give attribution. But that is up to you. Also, I wonder if there is a communication channel for the Thunderbird Add-ons site, since Mozilla Add-ons no longer hosts legacy extensions.

There’s in fact a whole Thunderbird section on here, and also various related channels linked on the addons.thunderbird.net site.

I should have thought to look for that… https://discourse.mozilla.org/c/thunderbird/addons