[SOLVED] Unclear errors, unable to install new .deb file

I have to install a new version of some software I am using, I tried the terminal command:
sudo apt install xxxx.deb
It comes up with an error:

Code:alex@alex-nuc8i7hnk:/$ sudo apt install /Downloads/qaewb.deb
Reading package lists... Done
E: Unsupported file /Downloads/qaewb.deb given on commandlineSo, I searched and tried some ideas, but am getting the following errors:

Code:alex@alex-nuc8i7hnk:/$ pkcon refresh
Refreshing cache [=========================]
Loading cache [=========================]
Downloading packages [=========================]
Running [=========================]
Finished [=========================]
Fatal error: E: The repository 'http://ppa.launchpad.net/clipgrab-team/ppa/ubuntu focal Release' does not have a Release file.
W: Updating from such a repository can't be done securely, and is therefore disabled by default.
W: See apt-secure(8) manpage for repository creation and user configuration details.

alex@alex-nuc8i7hnk:/$ apt update
Reading package lists... Done
E: Could not open lock file /var/lib/apt/lists/lock - open (13: Permission denied)
E: Unable to lock directory /var/lib/apt/lists/
W: Problem unlinking the file /var/cache/apt/pkgcache.bin - RemoveCaches (13: Permission denied)
W: Problem unlinking the file /var/cache/apt/srcpkgcache.bin - RemoveCaches (13: Permission denied)