There are several ways you can clear the Sucuri Firewall cache:

Dashboard Cache Options

To clear all page and file cache at once, go to Performance ,and from Clear Cache – Global, click Clear Cache.

To clear the cache for individual pages or files, go to Performance, and from Clear Cache – Per File,

enter the file URL you wish to clear, and then click Clear Cache.

API Cache Options
If you’d like a faster way to clear your site cache, you can also use the Website Firewall API.

Log into the Website Firewall dashboard > go to API >  click API Details > click  Clear Cache

(Website Firewall API v1) button. Next, you will clear the cache using the Website Firewall API.

Each site does have their own unique API key. If you require a large list of clear-cache APIs for your

domain inventory, notify your account rep who can retrieve that list for you.