Problem with upgrade of the system (Grafana issue?)

Hi,

I have openhab and Grafana on RPI3 Buster release.
Currently I can observe that there s no possibility to do update/upgrade
I see message like below:

[14:49:04] openhabian@openhab:/etc/openhab2$ sudo apt-get update && sudo apt-get upgrade
[sudo] password for openhabian:
Get:1 Index of /debian buster InRelease [32.6 kB]
Get:2 Index of /raspbian buster InRelease [15.0 kB]
Hit:3 InfluxData - Package Repository buster InRelease
Ign:4 https://dl.bintray.com/fg2it/deb buster InRelease
Ign:5 https://dl.bintray.com/openhab/apt-repo2 stable InRelease
Err:6 https://dl.bintray.com/fg2it/deb buster Release
404 Not Found [IP: 3.122.12.180 443]
Get:7 https://dl.bintray.com/openhab/apt-repo2 stable Release [6,051 B]
Reading package lists… Done
E: The repository ‘https://dl.bintray.com/fg2it/deb buster 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.

I’m beginner and honestly I’m not sure what I should do to repair this issue.
It seems to be problem with Grafana

This is not related to Grafana.
This is a problem that is related to dl.bintray.com - the place where openhab repository is located.
It is a known problem.
Somewhere in the forum a workaround is mentioned. In case I find it I will add it here.

EDIT:
The workaround that is mentioned in the other thread suggests to manually download the deb files using the wget command. You also could use a browser to do so. For this you would need to know where to download the files. Then you could manually install the files.
Would you like to continue to try that way ?
I also saw this several times but I never downloaded the files to the local filesystem to manually install the files. Instead I retried the installation a few days later. Might be that I had more luck…

Thanks for clarification I can use wget but what file I need?, what syntax should I use?

Execute the following commands

apt-get update
apt-get download --print-uris openhab2 openhab2-addons| cut -d' ' -f1

The second command will print out the URLs of both packages ( openhab2 and openhab2-addons ).
The package management will take care about showing the URL/package that is related to your system architecture.

I have two locations of packages as a output from commands above
I assume that now I should use wget
How to install it manually after downloading?

Indeed it should be two locations as openhab2 and openhab2-addons are two packages. Thus one location per package.
You may use wget, curl or a browser to download the files.
Then you can use

cd <into directory containing the two files>
sudo apt install ./<filenameOH>.deb ./<filenameOHaddons>.deb