You need the http:// part if you're going to do links like that.

Amazon is a bit tricky. https://www.amazon.com/BETAFPV-Quadcopter-Silverware-Firmware-Controller/dp/B07CV8WVZ2 $45 for a thing. Requires a controller though.

I was going to jokingly suggest getting an E011 at another $40 just for the controller, but that doesn't ship from amazon.

Actually, how about a Jumper T12 controller? That'll do the bayangprotocol that the BetaFPV thing wants.