I saw several unanswered questions related to this when I was trying to accomplish this task. I found an answer.
Settings -> WiFi -> Edit
brings up a list of all of the WiFi networks / passwords stored on the device. You can hit the “-“ symbol in red to delete a specific network.
Quite correct - but only if the iPad has been updated to iPadOS16.x.
How to forget a Wi-Fi network on iPhone, iPad, or Mac - Apple Support
For earlier versions of iOS/iPadOS, you can only delete an individual WiFi network when within range - or through resetting network settings which will delete all WiFi networks from the device:
iOS/iPadOS16 and later
Settings > General > Transfer or Reset iPad > Reset > Reset Network Settings
iOS/iPadOS15 and earlier
Settings > General > Reset > Reset Network Settings
Quite correct - but only if the iPad has been updated to iPadOS16.x.
How to forget a Wi-Fi network on iPhone, iPad, or Mac - Apple Support
For earlier versions of iOS/iPadOS, you can only delete an individual WiFi network when within range - or through resetting network settings which will delete all WiFi networks from the device:
iOS/iPadOS16 and later
Settings > General > Transfer or Reset iPad > Reset > Reset Network Settings
iOS/iPadOS15 and earlier
Settings > General > Reset > Reset Network Settings
Manually removing stored Wifi networks
