In case the Reset App is not functioning properly on your iPad, you will need to perform a restore of the software on the device using a computer. To do so, you will need a computer with the most current version of iTunes installed or with macOS Catalina (10.15) or newer. View Apple’s support article on how to perform the erase/restore.
Before performing the Restore, it is recommended to turn off the Find my iPad Feature in the Settings App on the device and any data you want to keep is backed up to another device or the cloud.
The restore takes about 15-30 minutes, and the setup will take about another 10 minutes. You may also need your iPhone or another device that has your Apple ID signed into it to verify your account.