File name format. How to save a file with an underscore

I have thousands of picture files from my drone video/photography work and would like to store on my DS220+ …
These file names have an underscore in the name by default. I get an error when trying to save to a folder in file station - any suggestions? I thought about renaming - but geez… thousands of pics and videos.

Just tried renaming a photo and copying it to File Station > Photo with a file name including an underscore and it saved without issue. I’m using a DS220j Synology NAS with DSM 7.1 so your question does not seem to make sense to me.