@yerrn 

As of now, HTTP4 client is not officially supported in Pega version 24.1.2. There is no update or confirmation from Pega indicating that HTTP4 has been added in this version. If you need to use HTTP4 for any integration, it’s better to stick with the standard HTTP or HTTPS connectors provided by Pega. You can also check the latest release notes or documentation for version 24.2 or higher to see if support has been added. If HTTP4 is critical for your use case, you may consider raising a support ticket with Pega to ask for guidance or a possible workaround. For now, it’s best to use the supported methods that come with your current Pega version