This is from Grok:
General Profile Anonymity: If someone creates a profile with pseudonyms or uses a fake name, other users generally can't see their real identity unless:
The person shares personal information that can be traced back to them.
There's a legal intervention, like a subpoena or court order, where Facebook might disclose user information to law enforcement.
To create a new profile on Facebook:
On Mobile:
Open the Facebook app on your phone or tablet.
Tap on your profile picture at the bottom right corner (on iOS) or top right corner (on Android).
Tap on the arrow or three lines menu (if you see it), then go to Settings & Privacy.
Scroll down and tap Profiles.
Tap on "Create New Profile". If you don't see this option, check if you have the latest version of the app, as this feature is relatively new.
Fill out the information for your new profile, including a name for the profile, and then tap Next.
Add friends, follow pages, and customize your new profile as you like.
On Desktop:
Go to www.facebook.com.
Log into your main account if you're not already logged in.
Click on your profile picture in the top right corner of the screen.
From the dropdown menu, select See all profiles.
Click on "Create new profile" at the bottom of the profiles list.
Choose a name for your new profile and click Next.
Complete the setup by adding friends, joining groups, or following pages.
Note:
You can have up to four additional profiles with one main account.
Each profile will have its own privacy settings, notifications, and friends list, but they are all linked to your primary account.
Your main profile won't show that you have additional personal profiles unless you choose to disclose this information.
These instructions are based on the most current features available on Facebook at the time of this writing. Make sure your app or browser is up-to-date to access the latest features.