Works perfectly for me. I am currently using Firefox 90.0.2 and Telegram 2.9.3 and I don't have any issues.

Sigue funcionando a la perfección con Firefox 90.0.1 y Telegram Desktop 3.1.1.
Para los que no leen los comentarios del desarrollador de mas abajo: si te abre y cierra una pestaña y parece que no hace nada o no funciona, abre esta URL en el navegador y marca la casilla y acepta:
https://telegram.me/share/url?url="test"
A partir de entonces funcionará correctamente. Es un fallo de Firefox, no de la extensión

Works well with Telegram Desktop on Ubuntu Linux 👍

Very good complement to Firefox and also works perfect.
It would be possible to add a function to send and publish the link to a given group without confirmation through the configuration of the plug-in? Telegram groups have an address that can be used for this. If confirmation is required anyway, this function would be useful as well.
This is useful if you are a group administrator or group owner and want to share something, it is also useful if you are logged in as a user in another group and want to send something to your group, save time.
Additionally in configuration there could be a check mark to ask if you want to send the link to another group or not, if you want to use this configuration or not and similar options.
I will send a copy of this revision through the addon support email.
Greetings.

Is it possible to make it close telegram website after share notification pops out?

Does what it should. Thanks!