GHL Wizard Settings Page:
After installation, you will get a menu "GHL Wizard" on your dashboard. By clicking on that button you will get the settings page. Here on the GHL Connection tab, you can get 2 fields client ID & client secret, But it's OK if you don't want to create a new App to get your own client ID and client secret. Keep these 2 fields blank and hit the "Connect Your Location" button.
Select Your Location:
When you click on the button "Connect Your Location" you will be redirected to gohighlevel marketplace to get connected with your GHL location. if you are not logged in, you need to log in to your gohighlevel and you will see the list of your locations. select one location that you want to connect with your WordPress website.
After selecting your location, you will be redirected to your "GHL Wizard" settings page and you will see a location ID that is connected to your WordPress. Congratulations, You did it.