No new messege badge counters on Slack application icon in the Ubuntu dock

I use Ubuntu 21.10 and Slak 4.24.0. But badge counters do not work and do not appear on Slack in the Ubuntu dock even if someone mentioned my name or sent me a direct message.

At the same time badge counters work for the Evolution email client and for the Telegram app.

Please see screenshots below

How to get badge counters working on the Slack app when a new message arrived in Ubuntu dock?

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