How to fix my AirPods Pro leaking a sticky black fluid?

My right AirPod pro has had a small crack in the plastic on the stem towards the bottom for a bit over a year with no issues, until recently it started leaking a sticky black fluid with a metallic smell. Can this be from the battery or just usage? The AirPod works fine, am I okay to continue use?

[Edited by Moderator]

Original Title: AirPod leaking