There are lots of options in this space - tools like LogRocket can record a whole user session, capture all the interactions and errors, and let you watch a replay in order to see how the error came about, and what the user did afterwards. We use it at work (also a B2B web app, no affiliation with LogRocket) and it's a very useful too.
You have plenty of other options - Rollbar and Sentry come to mind, though I've never used either, but have heard good things about both.
Lastly, if you have back-end monitoring already then you might want to see if that solution has a front-end integration. Datadog does, for example (also a Datadog customer, but again no affiliation with them). Warning: Datadog is powerful but can be a bit overwhelming with features, I probably wouldn't start there if you just want some front-end error tracking.
https://logrocket.com
https://rollbar.com/
https://sentry.io/welcome/
https://datadog.com
