Creating Sankey with fixed Nodes (x,y Coordinates) - Plotly Sankey

Hello everyone!
I am new to Plotly and have a question regarding the amazing Plotly Sankey functions.

Setting up a basic Sankey is nicely made with giving sources & sinks. But how can I set the x & y-coordinates for the nodes in the diagram? I found the “Defining Node Position” part here:

But the results are unfortunately not satisfying because they are not precise and I actually want to place each node on a specific point onto the background image.

Does anyone have a solution or a workaround-idea?

Thank you very much guys!

Sankey wasn’t made around cartesian axes. Also, note that x and y are fractions of domain size and should be between 0 & 1.