It will depend on what the actual product is and who the intended customers are.
It may be that you just need to start hitting that phone and talk with potential customers. Validate they want to talk with you.
Also a waitlist and building an email marketing can be very strong from the start. And it will help having that list when for instance you launch on ProductHunt.
Or combine your software development with service based (custom) approach, where you are being paid to create the toolset basically.
There is a problem when there is no product-market fit.