GNU/Linux Lubuntu Installing AMD Open Source Drivers Guide
How to Install AMD Open Source Graphics Drivers in Lubuntu LTS GNU/Linux desktop – Step by step Tutorial.
And Open Source AMDGPU Graphics Drivers for Lubuntu Linux includes Updated Free Graphics Drivers for AMD/ATI Graphics Cards.
These drivers are based on the Mesa 3D stack and support modern AMD GPUs using the AMDGPU kernel module.
Especially relevant: as a complement you may be intesested also to the MESA Graphics Drivers Suite Setup.

1. Launching Terminal
How to QuickStart with Command Line on Lubuntu
First, Update the Apt Repo Sources with:
sudo apt update
Authenticate with the User Admin Pass.
If Got “User is Not in Sudoers file” then see: How to Enable sudo.
Contents