Our organization uses a custom Salesforce URL for user authentication through SSO. It looks like the integration uses the standard Salesforce login flow. Is there a way to customize this?
We provide the integration with Salesforce as a C# script. You can take it (install it for an extension) and make all the changes you need. When you have it ready, you can upload it to 3CX as a custom plug-in, as explained here: https://www.3cx.com/blog/releases/crm-integration-diy/