Where can I get an EF-EOS R adapter?

I ordered the R earlier today off of Canons website and I need the adapter since I don’t have the money for any of the RF lenses. The adapters are out of stock or on back order on their website along with pretty much everywhere else like B&H and Adorama. I assume everyone is buying them because of the R5 & R6 releasing soon.

I want to be able to use the camera when I get it since I’m shooting my first wedding next week. (WOOHOO!!)

Are there any reliable websites/sellers that sell them that might have them in stock? I just don’t want to get one off of a sketchy 3rd-party site and end up getting ripped off. I was also wondering how long their products are usually on back order for?