To mass invite people to a Facebook group, follow these steps:
1. Open the Facebook app or access Facebook on your computer.
2. Navigate to the group you want to invite people to. You can search for the group in the Facebook search bar or go to the Groups section on the left-hand side of your News Feed.
3. Once you're on the group's page, locate the "Invite Members" button. On the desktop, it is typically found on the right-hand side of the group's cover photo, and on mobile, it is under the "..." (More) button.
4. Click or tap on the "Invite Members" button to open the invitation interface.
5. A list of your Facebook friends will appear. Scroll through the list and click on the names of the friends you want to invite to the group. You can also use the search bar to find specific individuals.
6. After selecting the friends you wish to invite, click or tap the "Send Invites" button to send out the invitations.
7. Facebook will now send the group invitations to the selected friends.
Note: Facebook's invitation feature doesn't allow for mass invites to people who are not your friends on the platform. If you want to invite people who aren't your Facebook friends, you will need to send individual messages or use other methods like sharing the group link.
Keep in mind that Facebook's interface may change over time, so if the steps mentioned above are not accurate, please refer to the latest Facebook documentation or help center for detailed instructions.