How to approve screen sharing once on Ubuntu (Wayland)

The easiest moment is right after you set the Agent up, while you're at the PC. On Wayland the Agent offers it straight away with a window called Approve screen sharing once on this PC. The help article on RemoteAccessApp on Linux covers installing and setting up the Agent first.

1. 1

   Step 1: Open Screen sharing

   If the window isn't open, click the RemoteAccessApp icon at the top right of the screen and choose Screen sharing…. If the Agent started in the background, a notification asks the same thing: click Set up on it.

2. 2

   Step 2: Click Set up now

   The Agent's window steps out of the way, and Ubuntu shows its Remote Desktop dialog.

3. 3

   Step 3: Turn on Allow Remote Interaction

   This lets your mouse and keyboard work in a session. Without it, you can only watch.

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   Step 4: Keep Remember This Selection ticked

   This is what makes it a one-time question. Untick it and Ubuntu asks again next time.

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   Step 5: Click Share

   The Agent's window comes back and says Screen sharing is set up. Remote sessions now start without anyone clicking at the PC.

If you skip the step above, the dialog appears the first time someone connects instead. That includes the first time you help someone on a Linux PC with a one-time code: they answer it while you wait. The order is always the same:

• First, RemoteAccessApp's own prompt. Allow remote access? names who is connecting, unless unattended access lets their console in.
• Then Ubuntu's Remote Desktop dialog. A notification at the PC lists what to pick: turn on Allow Remote Interaction, keep Remember This Selection ticked, click Share.
• Meanwhile, the person connecting waits. Their session says the person at the computer has to approve screen sharing once, and starts as soon as they click Share.

• The Agent says the desktop didn't remember the approval. Remember This Selection wasn't ticked. Open Screen sharing… and answer the dialog again with it ticked.
• It says screen sharing wasn't allowed. The dialog was cancelled, so nobody can see the screen. Click Set up now and click Share this time.
• You can watch but not click. Allow Remote Interaction was off. Click Set up again in the same window and turn it on. Set up again is also how you change which screens are shared.
• It says this desktop can't share its screen. Some smaller Wayland desktops don't offer screen sharing to apps yet. Choose an Xorg (X11) session at the login screen instead; there's no dialog there at all.

Not sure which you're on? Open a terminal and run:

echo $XDG_SESSION_TYPE

wayland means this guide applies; x11 means there's no dialog to approve.

The approval only lets RemoteAccessApp share this desktop's screen. It doesn't decide who may connect: that's still the Agent's job, with the Allow prompt, or unattended access for consoles you trusted, and a banner with End in every session. While someone is connected, Ubuntu also shows its screen-sharing icon in the top bar, and Stop sharing there ends the session.

Once it's set up, you can reach the PC unattended, and unlock it from your side if it's locked. See unattended access on Linux and unlocking a locked Linux PC. For the background, read X11 and Wayland explained. The whole setup on Ubuntu, from install to first session, is in how to access an Ubuntu desktop remotely.