To let a trusted person remotely control your Ubuntu desktop from their Ubuntu machine, use:
1. Ngrok to provide an IP address as one usually don’t have a public IP.
2. Remmina Remote Desktop Client.
Register at ngrok if necessary
Download ngrok to your computer (the one you want somebody to have access to).
Go to: https://ngrok.com/download
Download the necessary version.
In case of necessity check whether you have a 32-bit or a 64-bit OS.
$ uname -a
A 64-bit Ubuntu will show:
Linux michael 5.8.0-53-generic #60~20.04.1-Ubuntu SMP Thu May 6 09:52:46 UTC 2021 x86_64 x86_64 x86_64 GNU/Linux
Result for 32-bit Ubuntu:
Linux discworld 2.6.38-8-generic #42-Ubuntu SMP Mon Apr 11 03:31:50 UTC 2011 i686 i686 i386 GNU/Linux Login to ngrok and follow easy instructions