[AlexRav4xse]

Set the key to battery saver mode

Press the Lock Button twice while pressing and holding Unlock. Confirm that the key flashes 4 times.

After that you can lock your car with the key inside.

To take it out of battery saver mode, you just press any button on the keyfob.

 

[AlexRav4xse]

You can get a faraday bag for less than $10 on amazon. Just put the key in and close the bag. It will stop transmitting the keyfob's signal and you can lock the doors. Take it out and it works as normal.

Here's one as an example: https://www.amazon.com/Protector-Blocking-Double-Layers-Shielding-Anti-Theft/dp/B0B4DCLY87/

 

[AlexRav4xse]

But if the keyfob will not be detected how can you lock the doors?

Press the lock button inside the car on either the driver's side or the passenger's side and then close the door.