If you are running eLxr, it is strongly suggested to use a package manager like apt to download and install packages, instead of doing so manually via this website.

You should be able to use any of the listed mirrors by adding a line to your /etc/apt/sources.list like this:

deb http://mirror.elxr.dev/elxr bianca main non-free-firmware

Replacing mirror.elxr.dev/elxr with the mirror in question.