Visit the Facebook Developers website at https://developers.facebook.com/

Sign up for an account, and if necessary, register as a developer. Ensure you are logged in.

Select the Create App button, and then the Create an App page will open.

Select “other” on “create an app page” click next

On the "Create an App." page A popup window titled "Select an app type" will appear.

Choose the last option, which is "None."

Enter your desired App Display Name, such as "Rent Marketplace"

Provide a contact email of your choice. Business account information is optional.

Click "Create App."

In the left-hand menu, navigate to "App Settings" and then click on "Basic."

In the "App Domains" field, list all the domains from which you want Facebook login to work, excluding "https" , "www," or subdomains. For example: "example.qoreups.com" or "example.com."

Optionally, add your privacy policy URL. Save changes if needed.

Scroll down and click "Add Platform."

Select “Website”.

In the "Site URL" field, enter your full marketplace URL with HTTPS, and possibly with "www" or the subdomain. For example: "https://www.example.com" or "https://example.qoreups.com."

Click "Save Changes" at the bottom right. Optionally, add your privacy policy URL again if necessary.

In the left-hand menu, click "Add Product."

Scroll down to find "Facebook Login" and select "Set Up."

Select “Web” as your platform for Facebook sign-in.

Verify that your "Site URL" is correct and click "Save," then "Continue."

In the left-hand menu, under "Facebook Login," select "Settings."

Ensure the following settings are correct:

In the "Valid OAuth redirect URIs" field, add your marketplace address followed by "/confirmation" For example: "https://www.example.com/confirmation." or "https://example.qoreups.com/confirmation."

Check that the "Deauthorize / Deauthorize Callback URL" section is empty.

Click "Save Changes."

From the top bar, switch from “development" to "Live" to make your app live.

In the left-hand menu, click "Dashboard." Your app should now be public, indicated by a green dot. Also, you need your business verification.

Your app is now created, configured, and live. However, there's more to be done!