www.makemkv.com

Or does program do it once per day? How it work?

I did send in 4 keys to admin email last night, hopefully they got it, as file attachment expire in 24 hour. I would PM admin to ask that, but you have to have more posts for that permission.

If enabled, MakeMKV will download the hash key file as needed, usually at program start-up.

You could manually fetch it, but I don't know the URL myself.