Invite some subset of users to become beta testers. Create a Slack channel for them and engage there. Invite users for 45 min 1:1 calls where you ask them to do

Invite some subset of users to become beta testers. Create a Slack channel for them and engage there. Invite users for 45 min 1:1 calls where you ask them to do a few tasks they usually do using your product. Observe them, take notes, ask them why they do stuff the way they do, brainstorm about new features, etc. Pay well for these calls.