STH-ETH 250 Reset Welcome Code

I installed the new Smart Things app and I am trying to add by Smart Things Hub (STH-ETH 250) I no longer have the Welcome Code that it is asking for. How can I get it or reset the hub? I have the serial number. Any assistance would be greatly appreciated!

Best method is to contact ST and provide them with the serial number by providing a photo. Also, have you checked in the battery compartment? Some of the v2 hubs had it imprinted inside.