Saving a custom stamp

I'm doing a custom stamp with an automatic date on it. I use this script on the calculation script: event.value = util.printd("mmm dd yyyy h:MMtt", new Date());

I am about to save the pdf file of my custom stamp but this notification appears.

So, I rename the file and save it to this path: User Path ---- Window C:\\Users\User\AppData\Roaming\Adobe\Acrobat\DC\Stamps

However, as I try my custom stamp on a random PDF file it doesn't exist in the stamp list. Only the older version or the static version of my custom stamp is on the list, the edited version which is with the automatic date isn't there.

Do I need to close the adobe acrobat DC after saving the stamp?

How to solve this?

and Where should I save my custom stamps?