There could be several reasons your AirPods are not charging. You could have dirty contacts that are making it impossible for the AirPods to connect with the charging case, there could be something blocking your case's charging port, meaning it's actually the problem, or there could be software issues at play. You may even find that something simple like a dead AirPods case is the issue.
These troubleshooting steps will help you determine if you can get your AirPods charged and working again.
Charge your AirPods. It sounds counterintuitive, but it’s possible you haven’t put your AirPods in their case to charge them in a while, even if you thought you did. Just to be sure, drop the AirPods into the case and wait to see if the charging light comes on. If it does, there might not be anything wrong with your AirPods.