I don’t need to use assistive touch yet to purchase something in the App store it insists on it!, even if the app is free. I want it gone.

Can you show us a screen shot of it asking you to use assistive touch? You don't have Touch ID on your iPhone but you do have Face ID. If there is a message that comes up on the upper right side of the screen it is asking you to double click the side button to continue and will then use Face ID.

Do you mean you're asked for your fingerprint? That's called Touch ID, and it's normal for the App Store to do that, even for free apps.

AssistiveTouch is something different.

I have never seen that. Is it possible your side button is broken? Regardless, I would suggest you click on the Get Support link at the top right of this page to start the service process.