How to build a community for a startup?

I'm currently building a document AI copilot, that answers any question about any document a user uploads & generates content about documents, called DocGPT (https://docgpt.io).

Over the past months I did everything I could to make the product better. There were always a lot of bugs to be fixed and features to be added. Now the situation has changed a bit: I'm starting to generate the first revenue & the product actually seems to have become useful for my customers, which is absolutely great imo! :)

I feel like now is the time to build up a community to further increase the growth of DocGPT, but first and foremost to get feedback from customers to get a better sense for what my customers actually want.

Until this point I relied on getting feedback via email from a very small number of customers, but I want to drastically expand that. I set up some social media accounts on LinkedIn (https://www.linkedin.com/company/93658380), Twitter (https://twitter.com/docgpt_io) and Instagram, but it seems very, very hard to even get a single person to register on DocGPT via social media, not even mentioning getting valuable feedback from them.

How do you guys handle that? How do you build up your communities? Do you have any tips for me?

Thank you very much in advance & best regards!