In the iOS SmartDry App:
Navigate to /Smart Speaker Setup/ Now Enter the email associated with your Smart Speaker account / Tap "Register Account"

In the Android SmartDry App v6.2+:
Navigate to /Smart Speaker Setup/ Google Assistant/  Enter email associated with your Smart Speaker account

Once account has been registered in the SmartDry App:  

Use this link below to get to the Google Speaker SmartDry Functionality via :
https://assistant.google.com/explore/search?q=smartDry

Then follow the prompts.