Building modular asp core angular application

I'm here because i'm facing an issue. At our company, we decided to build an asp core with angular front end application. And we want to publish it to our intégrators. But they may want to add specific developpement on their side on our applications for specifics clients needs. So how is it possible for them to add code to our application, on the front end part (angular )as well as the backend part (asp core) knowing that we will give them a compiled application. We do not want them to have access to the source code ...

It's like for odoo for example you can add pluggin to it we would like to do something similar. Do you guys know how it is possible in asp core + angular 7 ?

Thanks in advance, Looking forward for your advices A.MOULAY