This pop-up appears because of Apple's Handoff feature, which enables a Universal Clipboard across your Apple devices. When you copy something on a nearby device like a Mac, your iPad offers to paste it into Concepts.
If you do not use this feature, you can disable it in your Mac's System Settings.
How to Disable Handoff on macOS
- Open System Settings on your Mac.
- Go to General, then find AirDrop & Handoff.
- Turn off the setting for "Allow Handoff between this Mac and your iCloud devices."