In reactive/web, I think there isn't that option, even in terms of security. At least was what I read in this topic where is asked if is possible of doing that using javascript

https://stackoverflow.com/questions/55489025/it-it-possible-to-use-javascript-to-save-a-file-to-specific-directory

"It is not possible... fortunately! Imagine what would happen if JS which runs in your browser could change your filesystem. The security hole would be so big that everyone would (and definitely should) stop using the Internet."

The user is the one who chooses from its side.

On mobile, you can use the file plugin.

What I found on the web was just this.

https://www.outsystems.com/forums/discussion/74367/how-to-set-download-file-path-in-a-tranditianol-web-app/