Your approach to using flows are not the standard way.

Usually you would make a field for a flow, and "a function" / "some functions" that emits data from that flow.

Then, wherever you want to use it, you initialize that class at first (via injection or anything else). then start observing that field.
in order to populate that flow and make it deliver some data, you would need to call the function that emits data to that flow instead.