Finally, I can say that my application reached 1.0 status. When I released the initial version, users were able to create data maps and then export them to PNG or SVG. From now on, interactive maps can be published and embed on the website (via iframe). I hope this is something that will allow me to acquire more paying customers.
Example of interactive maps: https://datamaps.world/projects/europe-housing-price-statistics
Amazing new is that I have one paying customer already. This is the first time I got paid for my side project. Truly empowering feeling.
A few weeks ago, I was contacted by one of the users and asked if I can add a certain feature. Of course, I replied yes, but mentioned that this will be available for paid users. Funny thing was that I was planning to build it anyway. And after a couple of emails back and forth I received my first payment ever!