Issues with updating HA, add-ons and installing new add-ons

Dear Community,

I cannot update Home Assistant, addons or installing new addons.

Example1:
I tried to update home assistant operating system from 9.4 to 10.1. I got the following error message:

Remark: Rasberry Pi is connected to router (FritzBox7590) and internet connection from router was verfied via PC and Tablet.

Example2:
I tried to install the Advanced SSH & Web Terminal Bit it failed with the following error message. I appreciate help with this issue, as I am still learning.

Regards, Jens