Quick Assist

In Windows you can use Quick Assist to help someone by sharing their screen.

In the search bar, type Quick Assist.
Click on the Quick Assist App.

Alternately on the Start menu, select Windows Accessories, and then Quick Assist.
The shortcut key combination is Ctrl + Windows key + Q.

The Quick Assist window will be displayed.

Choose Give Assistance, a security code is displayed.

The other person also launches the Quick Assist App.
In the Get Assistance section, they enter the security code and click on Share Screen.

Choose Take Full Control, for control of the keyboard and mouse or View Screen to only view the screen.

Click on Allow.

While a Quick Assist session is running, it will automatically reconnect after a reboot.
The person providing help must be signed into their Microsoft account.
The person sharing doesn’t have to be logged in.
In the background port 443 and RDP is used.