How to clear Nginx Proxy Cache?

How to clear Nginx Proxy Cache?
I cleared the folder, it was 4GB, but the disk is still full.

CentOS 7.9.2009 x86_64(Py3.7.9)
It looks like the panel is broken.

[root@mail ~]# cd /www
[root@mail www]# du -sh *
619M backup
4.0K php_session
6.6G server
1.1G swap
28M vmail
3.1M wwwlogs
2.5M wwwroot

aaP_hjjj41801
Maybe SQL log make Gigabytes of data?

Hello, the panel is reading from the system. Is the problem solved?