Hey! You can launch conversion Meta Ads (Facebook Ads) optimized for subscribers or registrations/deposits using TG Tracker
[URL unfurl="true"]https://fb-killa.pro/tools/TG_Tracker/[/URL]
That way facebook can see who actually joined your group (channel/bot)
You only pay $0.03 per subscriber event
Also regarding your iGaming offer - for good results you can try launching ads to a telegram bot with the Mini App and setting up postbacks to receive reg/dep events from the advertiser automatically, and we will match and forward them to Meta Ads (Facebook Ads). You can create a custom funnel for your offer and even pass subids (UTM) and test different funnels.
This is also good for player retention, because they can log in straight into their account from the telegram bot. can send push notifs
We have a no code visual bot builder that you can use to construct your offer, so you can do everything in our service.