I have an old ipad that I want to sell that has my old apple ID signed into the icloud. That apple ID is "no longer supported" so there is no way for me to reset the password so I can sign out of it. I have tried every article and video to no help.

 if you are the original owner, contact Apple. They can remove the Activation Lock if provided the required paperwork. Either take the device, the original purchase receipt with the serial number, and a photo ID to the nearest Apple Store (if it has reopened)

Genius Bar Reservation and Apple Support Options - Apple.    

or contact Apple ID Support. 

 Apple ID - Official Apple Support.    

Contact Apple for help with Apple ID account security - Apple Support.  (Link doesn’t always load)   

Get Support      Work through the screens to get a chat option. 

Apple Support schedule phone call

https://twitter.com/AppleSupport       People have posted it may take an hour or more to get a response.

See What to do before you sell, give away, or trade in your iPhone, iPad, or iPod touchhttps://support.apple.com/en-us/HT201351