Trying to use iPhone data with my new iPad

[JDeca]

I get a greyed out box that says I can activate my iPhone data plan with my new iPad but it says I need to connect to WiFi for this to become available and when I connect to WiFi the option just disappears until I turn off the WiFi again, I've tried resetting my iPad and turning off and on with airplane mode but nothing seems to be fixing this is there anything else I should be trying? Thank you.

[PandJ2020]

Are you trying to tether your iPad to use the data from your iPhone?

If so you need to enable the personal hotspot on your iPhone and connect to it (via WiFi) from your iPad.

[JDeca]

There is an option on my iPad mobile data that allows me to use my eSIM from my iPhone on my iPad to have cellular data away from my phone but it is greyed out with WiFi off telling me to connect to WiFi but when I connect it disappears.

[63johnw]

Hi @JDeca  as mentioned by @PandJ2020  ypu need to set up a hotspot on your iPhone (also known as tethering) and connect your iPad to that. 

https://support.apple.com/en-gb/111785

[TimmyBGood]

@JDeca 

Apple says 

Join an existing iPhone plan

If supported by your network provider, you can set up a mobile data plan by adding your iPad to an existing iPhone mobile plan.

Make sure your iPad is running the latest version of iPadOS.

Go to Settings > Mobile Data > Join iPhone Plan, then follow the onscreen instructions.

If you can’t select Join iPhone Plan, make sure you’ve enabled Wi-Fi on the iPad, and that you’re signed in with the same Apple Account on both your iPhone and iPad.

https://support.apple.com/en-gb/119592 

I'd imagine there's a fair chance that a greyed-out option means not supported.

[PandJ2020]

Indeed. I would suspect not supported - but tethering via hotspot will work just fine... (I use it)