Please help, safety sense button.

Dear Everybody. I am hoping to get a quick guidance about the safety sense feature in prius alpha.

So I am about this close to purchase a new 2020 second hand prius alpha before I notice something odd. That is a missing button in Prius Alpha 2020 compare to Prius Alpha 2017.

If you see the photo that attached to this post, you can see that prius alpha 2017 have that button to adjust the proximity of safety sense (that is, how far our car to the front car until the warning alert is triggered). This is a key feature that I want in my car.

However such a button does not exist in the 2020. Even though the line assist button is exist in the two cars.

Now my questions are:
1. Does having line assist does not mean the car have that proximity warning feature (or we may call it safety sense).

2. If such a feature exist, where to do the setting if such a button is non-existent.

That would be all, thank you for your future help and information