i have a hp ipad can I get facetime video with it

There isn't such a thing as an "hp ipad." I suspect that you may mean an HP tablet. FaceTime will only work on Apple devices.

Also see: Use FaceTime with your iPhone, iPad, or iPod touch - Apple Support

Skype is an option that will work on both Apple and Android devices. https://www.skype.com/en/

There is no such thing as a HP iPad.

Only Apple makes iPads.

If you mean you mean you have a tablet made by HP, your grandson and you will have to download some other app that does video chat.

Google Duo, Skype are 2 I know of

iPad and FaceTime are a registered trade mark of Apple.

Only Apple makes iPad that can do FaceTime with other Apple devices (iPhone, iPod touch & Mac computer).

All other brands are called tablet.

Try Jonathan tips above.