How do I block a person from joining a WhatsApp group?

• To begin, open the app.
• To access further options, press the three dots in the upper right-hand corner of the screen.
• Select 'Settings' from the drop-down menu.
• Select 'Privacy,' then 'Blocked Contacts' from the 'Account' section.
• In the upper right-hand corner of this menu, press the 'Add' sign.
• Choose or search for the person you want to block.
• Go to the chat room for the group.
• Select your group's topic by tapping it.
• You'll now proceed to the administrator's chat room. In the upper right corner of your screen, press their phone number.
• Select 'Block' and then 'Block' once more.

Read More: Why am I not able to send any pictures or download any pics from WhatsApp?