"Upload to" vs. "upload on"

Generally you "upload to" and "download from".

You might express that you "uploaded from your laptop to your server", which uses both from and to.

You might say that you "can do the upload on that machine in the corner", but that refers to the machine you performed the command to upload on (the one physically in front of you), not the one you uploaded to (often the one uploaded from, but not necessarily).