To start, go to Stores -> Configuration -> IWD -> Address Validation


GENERAL


Enable
  • Enable / disable address validation at checkout

Allow Invalid Address Checkout
  • If yes, then customers with an invalid address will be able to place their order
  • If no, customer will have to provide a valid address to place order


CONTENT


Validation Pop-up Title
  • Specify the title of the validation pop-up. By default this is set to 'Address Cannot Be Verified"

Invalid Address Message
  • Specify the error message shown to the customer. By default this is set to 'Please review your billing address and make any necessary changes.'

Original Address
  • Specify the title for the customer's original address. By default this is set to 'Use original address:'

Suggested Address
  • Specify the title for the suggested address. By default this is set to 'Use suggested address:'


VALIDATION SETTINGS


Validation Service
  • Select the service that will be used to validate the customer's shipping address. Choose from: 

UPS
  • Test Mode - Set to 'yes' if you are using UPS test account. Set to 'no' if you are using live account
  • Login - Enter UPS account login
  • Password - Enter UPS account password
  • Access Key - Enter UPS account access key. Obtain a key.
  • Display Address Type - Show type (Residential/Commercial) of suggested address in validation pop-up

USPS
  • Test Mode - Set to 'yes' if you are using USPS test account. Set to 'no' if you are using live account
  • Account ID - Enter your USPS account ID

Google