Move files to a NAS

I have a Synology NAS DS218+. So I wish to move files from my download folder on my mac to a specific folder on my NAS.

I mount all the NAS Drives that I need all the time. Not sure how to describe the problem, but the rules I create are greyed out. on the destination folder.

Can anyone help me I have a screen shot of what I am seeing but not sure how to attach it.

You can post screenshots to a file hosting service. If you don't have your own, you can use imgur.com

Are they drives mounted at the time you are viewing the rules?