Forbidden (403) iFrame when viewing invoice in client portal

Hi, after a lot of digging I’m finally up and running with Invoice Ninja, including the sending of emails. However, the emails that are being sent with the invoices, include a button with a link to the client area (which seems to work fine, haven’t played too much with it yet). The issue is that the iFrame that is supposed to show the invoice, instead shows a 403 Error page. The setup is selfhosted on GoDaddy with a Installatron automatic installation. It seems the iFrame is trying to load

Display Styled Directory Contents

Embed the Appointments Booking Widget on your Webs - Page 2 - The Seller Community

HTTP error while getting salesforce features: 403 Forbidden - Match My Email

403 (Forbidden) errors when accessing Windchill pages post update in Windchill PDMLink

403 Forbidden Error - What Is It and How to Fix It {Tips for Webmasters}

If You Have Issues Using Keycloak behind a Reverse Proxy, Read These Tips, by Milos Zivkovic

403 Forbidden error for Intune objects in Graph Explorer - Intune

From single MySQL instance to HA - TIB AV-Portal

Medco Payer Sheet - AlohaCare

Adding iubenda's Privacy Policy to Your Site: Direct Text Embedding and API

Saferpay documentation JSON API Spec-Version 1.37

How to Fix the 403 Forbidden Error in 2024

Troubleshooting: Forbidden (403) - Canva Button Documentation