Thanks for getting in touch! Unfortunately there’s not going to be a super easy way to import products deployed outside of Octopus into Octopus, and it’d require configuring projects and their deployment processes/variables. From here, you can create releases of these projects to deploy to your customers. You could potentially ease the process of this setup by creating projects, tenants, etc. via the API (basically anything that can be done in the web portal can be done via the API). An example of creating a tenant using our open source .NET library can be found at the following page in our sample script repository.
We’ll be happy to help and provide more specific information depending on what exactly you’re needing to create, so feel free to expand more on your requirements and goals.