Nowadays mostly all sites are using the https protocol but the CSP disallow to embed them via
Does that external websites you have link on Dolibarr run with the same http Server with Dolibarr. e.g. your Dolibarr run on Apache Tomcat, http Apache, Ngix, Xampp, IIS? Does your external website run with the same Port? You need to inspect this factors before we can concluded. Well if you want to run on Dolibarr on https You considered also setting up the MySQL running https, Then you need to setup the https Server then you will be okay, Dolibarr as Flatform has nothing to do with [http or https], From the beginning - During Installation you must have to do this, If you are planning to do it with https, Please see the Picture Below
Thank you for your hint. Indeed it looks like the reason is to find in the same apache server and port I use for dolibarr and the website I want to include, in this case my nextcloud, . I will check to change the ports and then see if all works - Thanks for the hint,
