The LiteSpeed Crawler is a cache plugin that will regularly keep the cache for your websites updated to make sure that visitors don't encounter any uncached pages.
Per LiteSpeed's documentation, they do recommend that the crawler only be enabled if your server has enough resources.
The LiteSpeed Crawler can be enabled server-wide or per vhosts to reduce resource usage.
The following code block will need to be added to enable the crawler:
CacheEngine on crawler
For more details, you may refer to LiteSpeed's official documentation.