If your AirPods Pro (1st generation) make crackling or static sounds
Follow these steps.
support.apple.com
Apple extends AirPods Pro repair program for crackling or ANC issues
A year after the repair program was first introduced.
www.theverge.com
I purchased mine in jan 2020 and left bud started the crackling noise problem. I was pissed initially and stopped using them because they were out of warranty and it was very bad experience with the left side crackling when ever i shook my head.
Read an article in verge that apple replacing airpods for free so took them to apple store. Though i only had problems with left they replaced both for free.