They there,
Call Workflow Service derives the required input ports for calling from the actual workflow based on the Workflow Service Input nodes and their port types.
So go into your actual Workflow A, add a Workflow Service Input Port.
You need to add a Workflow Service input node with variable port.
See this post from @mlauber71 to see how that works ( a little hacky…):
Connect that variable output port to wherever your credentials are required, then save the workflow.
Inside your Workflow B then select Call Workflow Service and configure it. Select Workflow A and I think you can then “detect” what inputs are required.
Once you have done that and apply the changes your call workflow service node should have the corresponding inputs.
Let me see if I can find some screenshots to add here later…
Example of inside your workflow A:
Example of inside your workflow B to call workflow A:
