You've already created your app invite code and given it to your customer. Now they need to apply it to their consumer app. 

Customer will log into the Housecall (Consumer) App.

Once logged in, they will see this home page. They will click on the menu button in the top left.

Next the customer will click 'credit & invite codes.'

Have them enter your specific invite code that you set up on your Company Info page in your Housecall Pro account. 

After entering invite code, they will click 'apply.'

As the Pro, you will receive the following text message.

And email

Check out our tips on how to better connect with your customers.