GNU/Linux Ubuntu 20.04 Desktop Installing Latest Kernel Guide
Hi! The linked Tutorial shows you Step-by-Step How to Install Latest Linux Kernel in Ubuntu 20.04 Focal LTS Amd64 GNU/Linux Desktop.
Especially relevant, here are presented all the Best Alternatives for a Desktop Setup:
Xanmod Kernel
Liquorix Kernel
Mainline Kernel GUI Updater
But as a possible Alternative, you can try directly to Download and Build Linux following this Guide: How to Install Kernel from Source on Ubuntu.
GNU/Linux Ubuntu 20.04 Latest Kernel Installation Guide
Liquorix Kernel Ubuntu 20.04 Installation
Mainline Kernel Ubuntu 20.04 GUI Installation