Hello Henrik,
I think i was able to grasp your question through google translate.
When you create a new flow, it is important that you connect it to a supplier.
The supplier is either:
1. A homemade process, where you have inputs and outputs necessary to produce your flow, or
2. A process that exists in your database, with the necessary input and output information for the given flow.
The supplier tab is a dropdown menu, to the right of the flow you inputted into your process.
I hope this helps