I'm testing out The Dude and I need to make the version number the same. Dude server / CHR is currently 6.38.3 and other routers are on 6.38.1, rather than upgrading routers I want to downgrade the CHR to that same version. How can I do it though? I can't see a package for the CHR to download and copy over. Is there a way to make system-packages retrieve the 6.38.1 version and apply it?

upload the older NPK files, then run "/system package downgrade"

The question was how do I get the NPK files since there's no CHR package to download on the website
As it turns out, the answer is to use the x86 image, copied that over and clicked downgrade and it worked fine
Cheers

To get a older package you have to copy the link provided and past it a new tab of your browser. Then change the version number to the one you like to get and confirm.

example:

https://download2.mikrotik.com/routeros ... 6.38.3.npk

Change to:

https://download2.mikrotik.com/routeros ... 6.38.1.npk