Create an expiring link?

wdmycloud is working well to distribute video to my clients.

I wish to limit sharing of the link without taking the file out of the public folder if possible. Something like a dying link or expiring link as can be generated online. However when attempting to use these services and entering a copied link thru mycloud, the dialogue says “invalid url” so what would be the actual url to a file on my wdmycloud. There must be something else added to  http://WDMyCloud.device…

OR

Is there a more pratical method to restrict access to the link 

tks

Bruce

tootiny url shortener does the job