(I’m sure @qoheleth you knew this already) so just to clarify for future readers coming to this thread: With the solution that @joelp mentioned above, you wouldn’t need any battery.
OpenGarage is selling this, a hacked and wired version to handle Security+ 2.0 situation:
Other guys are selling something similar:
Or as @joelp mentioned above, you could get a ~$10 883LM button off Amazon or eBay or your garage door installer, and go DIY route.