Could anyone tell me what this is ?

[M4rc]

could anyone tell me what this white round plastic thing is on the door card?

 

[Steve Hales]

Looks like an Apple AirTag!

 

[WillWillWill]

It’s an emergency door release in case you get locked in the back with a flat battery. When you remove it there is a small wire on the back and if you pull it the door catch opens.