1) Deep expertise and network with potential customers
2) Ability to empathize and connect with your customers and sell the thing
3) Ability to build some sort of MVP
The deep expertise and empathy will allow you to hone in on the problem you know your customers will face, and so you can narrow down the "paradox of choice" of different features/products you can build. It'll give you a much better starting point for experimentation and iteration. Start small. Talk to these folks. Get people to validate your idea. If you don't have an existing network where you can talk to 30-50 customers (100 is better!), this will be a problem.
The empathy and salespersonship will allow you to get folks to give you feedback and/or pre-sell the thing. Maybe do consulting for them to earn revenue and testimonials. If you can't sell this, you're going to have a hard time.
Finally, you need to be able to build something that delivers value to your customers. You don't have to be the world's greatest programmer (actually, if you were that might hurt you more than it helps!) but you do need some programming chops. Maybe it's automation around an existing process (a chatbot that does something small). Or even a spreadsheet. Maybe it's a full-blown MVP. Either way, you don't have the revenue to pay a developer, and sharing context with someone that you can afford is likely very very difficult.
If you don't have these things, this will be really, really tough. If you do, it will still be very tough, but you have a much better chance of being successful.
Find a network of solopreneurs - either something local to you (where you can meet up periodically) or an online group. This will be invaluable as you run into challenges they solved, and then you can pay it forward for the people that will walk your path later. And, having a place to vent with empathetic folk will help keep you sane.
If you need any help, I'm happy to share my experiences solo-bootstrapping my company to 20+ people. Just email me matt [dot] rogish [at] gmail
Would love to connect to learn more about your experiences- I'm at firstname.lastname@example.org. Is there a best email to reach you at?