Screens lets you connect to a Mac without having access to a user account on that Mac. This is particularly useful when you need to connect to someone else's Mac on the local network.
You may connect to a remote Mac using that Mac’s Guest account. This method does not require the credentials for an existing user account on the remote Mac.
In the remote Mac’s System Preferences, click Sharing.
Select either Screen Sharing or Remote Management, depending on your chosen configuration.
Click Computer Settings and enable Anyone may request permission to control screen.
In Screens’ app settings, under More Settings → Macintosh Specific, enable Prompt for Screen Sharing.
In Screens, open Discovered, then tap and hold the Mac you wish to connect to.
Select Ask to Share Screen.
The user on the remote Mac must accept your Screen Sharing request.
Screens can connect to a remote Mac using an existing user account on that Mac in one of two ways:
Connect by logging in directly using the authentication credentials for that user account. This creates a background session on the remote Mac with that account’s customized Desktop and settings.
A user on the remote Mac logged in with that account’s authorization credentials may accept a Screen Sharing request.
If you have authorization credentials for an Administrator account on the remote Mac, you may connect directly to any active session on that Mac without prompting logged-in users for permission or confirmation. Remote Management must be enabled in the remote Mac’s Sharing preferences pane in System Preferences.