If your users sincerely have a pain point and think you can solve it, they will usually be happy to give you lots of input and feedback. This requires two thing

If your users sincerely have a pain point and think you can solve it, they will usually be happy to give you lots of input and feedback. This requires two things- intending to solve a real problem that users care about and being credible. You can increase the second aspect by communicating with and listening to your core and ideal customers, and getting to know not only if the problem matters, but what they care about in the context of that problem. There's a maxim that the value of your product is what your customers think it's worth. Learning from them why they care will increase your chances of building strong early relationships. Mechanically, regular communication that offers value via email, plus actual conversations that are informational not sales-y. From being the person doing this at both B2B and B2C companies in early stage.