Using iphone as car key

The CarKey feature built into iOS only works on a few newer vehicles, mostly BMW and Hyundai as I recall.

However, Toyota has a standalone app that offers this functionality, but it would only show up in the app if your car is equipped with Toyota’s Remote Connect feature.

Your vehicle must support that feature in order to use it. It's a relatively new feature that was originally only available for a small number of high price vehicles, so it might not be available on a 5 year old vehicle.

See Add your car key to Apple Wallet on your iPhone or Apple Watch - Apple Support

I'm not aware of any option like this. Can you find this listed in the owner's manual?

What does Toyota service say about this?