Enable SSL for Your Portal Site
Please make sure, you have a valid SSL certificate for your domain and applied to your site in IIS. You can find detailed instructions to enable SSL for your portal site at the link below;
Connect Portal Site to SharePoint
Before, you connect the portal to SharePoint Site Collection to use file upload widget at forms to upload documents to SharePoint, You should already have integrated SharePoint to your CRM (https://technet.microsoft.com ).
Fill in SharePoint User Credentials and Press “Save & Test Connection” to verify the portal is connected to SharePoint.