CiviCRM with Contact form 7
the Contact Form 7 with CiviCRM extension is meant as a basis for developers, it does not DO anything in itself. It enables sending data from a Contact Form to CiviCRM if you enter the data in the Contact Form in the correct way. But then something needs to happen on the CiviCRM side to. If you have developer skills, there is an example here: https://github.com/CiviCooP/be.werkmetzin.wpcivi

The API settings required are the site key and the API key required for CiviCRM API access. You can find more information here: https://docs.civicrm.org/dev/en/latest/api/interfaces/#rest.