How to get feedback from our users.

Hi!
We created a development streamlining tool to help developers and tech leads better manage their daily work. (https://www.keypup.io)

To collect feedback, we set up a short onboarding email series (4-7 emails during 14 days) and the last email is asking for feedback with a link to a Google Form. And it is not working!

We improve our features thanks to the feedback we receive, but it's hard to know what is working for developers. The more feedback we get, the better our services!

We've been recently listed on several platforms now (Product Hunt, Capterra, etc...) but we are still trying to find a more efficient way.

Any ideas to get valuable feedback from devs?
Thanks!