Excluding a blocked mirror

Hey, everybody!
When trying to install packages, e.g.
sudo dnf install fish
I’m getting errors

Errors during downloading metadata for repository ‘fedora’:

I suspect that this is because yandex.ru is blocked in my country, so I can’t access https://mirror.yandex.ru.
Can please tell me how to solve this problem? Can I exclude this mirror? Perhaps there is a better way?