Open an issue at https://github.com/srijan-kaiwart/flow-connector/issues — that is the fastest route and the whole history stays visible to you.
Before you write, the Help tab inside the extension has a "Report a problem" button that fills in your version, browser and recent log for you. That information is what makes a problem fixable, so using it saves a round trip.
This is a one-person project. Support is best-effort, and a reply usually comes within two working days.
Flow Connector is operated by an individual proprietor based in Madhya Pradesh, India. Full registered details are provided to payment partners and are available on request.