Wrap your current DataSourse Microflow in 2 different constructs, each for one device.
In the example below, if desktop is true I perform the interaction with the database. If false I create an empty list.
To determine the device use in the decision:
Replace my retrieve with your existing DataSorce Microflow if yours is complex for reuse, or decide to create 2 different DataSource Microflows.
Go Make It