When I try to use sudo apt update or install it gives me the following error:
Unable to connect to ir.archive.ubuntu.com
How can I fix the problem?
Go and search in https://downforeveryoneorjustme.com/
It will give you result is it down for you or everyone
Asiatech
orShatel
. Check this out: launchpad.net/ubuntu/+archivemirrorsping -c 1 ir.archive.ubuntu.com
and from the result of that I could see it on the link I provided in brackets, ie. launchpad.net/ubuntu/+archivemirrors (where I confirmed the output matched your country code - ie. IR to check what my conclusions)