2. Make the bot an admin of your group.
Please make sure you grant admin right to the bot to your group by following these steps:
Click on your Group name → Info → Edit → Admins → Add admin → Click on the bot name
On the pop-up with admin rights that will appear, please choose the following rights by switching toggles:
Change group info → OFF
Delete messages → ON
Ban users → ON
Pin messages → OFF
Add new admins → OFF
The navigation might slightly differ on desktop / web versions, please look for similar options.