How to add custom file storage feature

Our team use python version of on-premise sentry, and use Nginx as reverse proxy before two on-premise sentry instance.
The problem is: javascript and source map artifacts uploaded with webpack are stored on uncertain server which cause source map analyze feature don’t work quite often.
And our team has own own file cloud storage system and we don’t want to use either s3 or gcs storage.
So how could we add custom file storage feature with our own cloud storage system? Could anybody helps us with this problem?

Could anyone just tell me how to add custom file storage support just like s3 or gcs storage?
I not familiar with python.