I have a 5 lb OPD tank that has a quick connect. Is there an adapter I can buy to make it external threaded for filling? The reason is, no one here has an adapter so they can't fill a quick connect tank.
Your local propane supply store may have something.
Or if your quick connect fitting looks like this and you have the tool shown in the pic you could remove the QC for refilling.
That would sort of cancel out the usefulness of the QC though. Which IMO, isn't really that useful for this application anyway.
Or convert to a hose with a hand wheel at the tank end and eliminate the quick connect.
Whichever way you decide to go, you will find a better assortment of hardware at your local propane supplier's store.
And of course, much more expertise as well.