Starting with the new and improved Group Privacy Settings, WhatsApp tracker WABetaInfo reports that WhatsApp is remotely activating the feature in iOS beta version 188.8.131.52 and Android beta version 2.19.298. This includes the new Blacklist feature, that wasn’t introduced before. It is possible that you may not see the feature even after updating to the latest versions. The tracker recommends backing up chat history and reinstalling WhatsApp to get the latest configurations and activating the feature.
Check for the new option by going to WhatsApp Settings > Account > Privacy > Groups. The three options that now show up include Everyone, My Contacts, and My Contacts Except. When the feature first rolled out, there was a Nobody option, instead of the My Contacts Except option. This new option will let you select the users who have to gain approval before adding you to a group. You can either select a few users or click on the Select All option to include the entire contact list.
WABetaInfo notes that adding new contacts to your phone will require you to go and manually add that additional person to the list. The My Contacts option, on the other hand, will enable users you have in your address book to add you to groups, and the Everyone option won’t add any restriction.