Whenever I try to download a app “confirm with assistive touch” always pops up d

Instead of Double Click to confirm App Store purchases, it is looking for Assistive touch if you have enabled it on your device.

Hello,

I am thinking you likely accidentally enabled it with an unintentional triple-click. That will also turn it off for you.

Use AssistiveTouch on iPhone - Apple Support

"Tip: To turn AssistiveTouch on or off quickly, triple-click the side button (on an iPhone with Face ID) or triple-click the Home button (on other iPhone models)."

I hope this helps.

It would be better if you can please re-post with a screenshot, in order to understand the phenomenon better. Images/pictures speak louder than words. 

Please understand this is a public forum: While attaching a Screenshot, do not provide any personal credentials, such as IP address, Card detail, email id, apple id, IMEI number, Serial Number, Phone number, Order ID, if you are sharing a map ensure your location is not identifiable, etc.

Have you enabled Assistive Touch? Use AssistiveTouch on your iPhone, iPad, or iPod touch