there is only a serial number on the ipad no imei number
what do I use to identify the device I am using which is a series 7 ipad
Question marked as
Find the serial number or IMEI on your iPhone, iPad or iPod touch - "Learn how to find your iOS device's serial number, IMEI/MEID, CDN, and ICCID." -->
https://support.apple.com/HT204073
What number you actually need depends upon what you are trying to accomplish. Apple tends not to use IMEI for anything.