Various problems

[Rik002]

Many of the apt packages couldn't be fetched using apt update.
Microsoft Edge cannot sync workspaces feature , and Account Sync as well.
WhatsApp web cannot be accessed.

[himanshub16]

i think this tool might no longer be needed since newer versions of Ubuntu work well if you set proxy via system settings.
When I wrote this code back in 2015-16, they didn't work well.

If you are still keen on using it , can you please share the output of /etc/apt/apt.conf? (please hide sensitive info)