Output from apt update Question

[Jay Ridgley]

Good afternoon,

As part of my quest  for the answer to my scanner problem a suggestion 
was made to try:

sudo apt update
sudo apt install snmp snmp-mibs-downloader

apt update showed this as part of the output:
Err:6 http://ppa.launchpad.net/hplip-isv/ppa/ubuntu focal Release 

   404  Not Found [IP: 91.189.95.85 80]

and ended with this:
E: The repository 'http://ppa.launchpad.net/hplip-isv/ppa/ubuntu focal 
Release' does not have a Release file.
N: Updating from such a repository can't be done securely, and is 
therefore disabled by default.
N: See apt-secure(8) manpage for repository creation and user 
configuration details.

apt install ...

Reading package lists... Done
Building dependency tree
Reading state information... Done
snmp-mibs-downloader is already the newest version (1.2).
snmp is already the newest version (5.8+dfsg-2ubuntu2.3).
0 upgraded, 0 newly installed, 0 to remove and 1 not upgraded.

How do or can I fix the repository problem?

and How to discover what 1 not upgraded package refers to as not done?
-- 
Jay Ridgley
jridgley2 at austin.rr.com
Registered Linux User ID - 9115
https://linuxcounter.net/cert/9115.png
Registered Ubuntu User ID - 23320