-API Key: Enter your GetResponse API Key.
Go to Forms -> All Forms and edit one of your Forms. On the tab Emails & Actions you’ll see a + on the bottom right to add additional actions.
Click this button and add the GetResponse action.
-Campaign: Select the Campaign to which you want to add subscribers from your Form.
-Email: Select the Email Field from list of your form fields.
-Name: Select the Name Field from list of your form fields.
-Custom Fields: Select any other fields you want to send to GetResponse
You can add Opt-in checkbox by adding new field to your form.
Select GetResponse Opt-in field
Thats it ! You are all set to go.