If both your iPad and iPhone use the same AppleID and use iCloud, your devices use Apple’s Continuity functions to seamlessly switch between devices. As such, you can start an activity on your iPhone - and easily continue the task of your iPad.
When Continuity offers this facility, an icon will appear in the “Recent Apps” section of the Dock - with a “badge” icon representing the other device. Touching the icon will open the App and allow you to resume the activity on that device.
https://support.apple.com/en-us/HT204681
I hope you find this helpful in resolving your question.