Copy both the ACF file and the game folder to the appropriate Steam folder on a different PC and when you next start Steam, you'll find the new game listed.

How to transfer a Metro Exodus save game to another gaming PC By moving to the Epic store from Steam, the PC version of the new Metro game loses cloud saves.

OK, today my rant - copy protection mechanisms used on game CDs and DVDs which mean that you have to have the game in the CD/DVD drive in order to be able to play it.