You can allow your members to sign in to your community using their Apple ID with the benefits that brings such as FaceID/Touch ID and Two factor authentication.
Using this method, members can also protect their privacy by choosing to hide their real email address. Their account will be created using a relay email address unique to your community.
Sign in with Apple requires a paid Apple developer account that can be created at https://developer.apple.com.
Once you have an Apple developer account you can create the credentials needed.
Go to Certificates, Identifiers and Profiles.
Click on Identifiers from the side menu and then the + icon to create an identifier.
Choose App IDs on the first step and click continue.
Enter a description and Bundle ID. The description can be anything you like but your community name is a good one. The recommended bundle ID is the reverse DNS style of your domain name e.g. com.yourdomain.
Select "Sign in with Apple" from the list of capabilities and then confirm.
Return to the identifiers page, click the + icon again and this time choose Services IDs followed by Continue.
For the description you can enter the same as you did for the App ID above. For the Identifier field enter the same identifier as in the first step followed by .client e.g. com.yourdomain.client. This is your Services ID - make a note of it, since you'll need it later when setting up Invision Community.
Click Continue and then Register. You will see your service listed on the Services page. Click the service you just created.
From the capabilities list, again select Sign in with Apple and then configure. This is where you will add your community domain name.
First select the App ID you created in the first step above and then enter your domain name. If you only have one App ID on your developer account it should already be selected.
The return URL should be set as the path to your community followed by /oauth/callback/ e.g. yourdomain.com/oauth/callback
Click Next, then Done to close the popup. Click Continue then Save on the page.
After returning to Certificates, Identifiers & Profiles choose "Keys" from the side menu and then the + icon to create a new key.
Enter a key name select Sign in with Apple from the list of capabilities and click configure.
Select the App ID you created earlier and click Save.
On the page you are returned to, click Register.
A .p8 key file will now be generated. Be sure to save this key now as it can't be retrieved later.
Finally, return to the key details page and make note of your Key ID.
The Team ID can be found on the Membership page in your Apple developer account, or at the top of most pages when creating/editing keys and services.
You should now have a Services ID, Team ID, Key ID and Key file you can use to set up Invision Community.
In your Invision Community admin control panel go to System > Settings > Login & Registration and click "Create New" on the Methods tab.
Choose Apple from the list of handlers.
You can now enter the credentials obtained above and upload the .p8 key file and set the other settings according to your preference.
A test of your settings will be performed and if everything is correct Sign in with Apple will be enabled on your community.