On amazon there are magnetic add-on locks with 800lbs to 1200lbs of hold force.
They work with rfid. Cards, remotes, proximity, keypads.
Cheap.
Or
I rigged a generic power-door-lock to the interior up-down primary latch on mine. It took about 15 minutes and it has a wireless remote. $15 for four actuators. Edit(now $39)
But
I removed it because to leave it in place it required a bit of intricate work on the screen door it interfered with.
Turns out I didnt care enough to spend 3 hours jacking with the screen.
So, you're $15 and three hours from making your own.
https://www.amazon.com/InstallGear-K...s%2C749&sr=8-2
(Toss out three of them)
Both are easy.