Build Cordova plugin based on an existing SIP call software

We would like to integrate an third party software (SIP call) into our software, so that we can apply the SIP video call functions in our software. Our software is developed in Cordova and the third party is in Native so we need to convert their functions as cordova plugins. The third party software is an intercom mobile app. Visitor press the door bell, residents will receive the SIP call from door bell panel. Door bell and phone can talk to each other, and phone can receive the video from door bell camera. The android third party software source code and SIP settings will be provided. I can keep the sample door bell on, and you can test connection all the time. We only need the cordova plugin to let our app gain the same functions. Additionally, We also need a demo cordova app to show the functionality. P.S.: This is a continued project that we need integrate various third party app into our all-in-one app. So we may post multiple project with different functions.