Usage
The "cacheflow" extension provides a command-line interface (CLI) command called cacheflow:
for cache
flowing operations. To execute the command, open a terminal or command prompt and navigate to the root directory of your
TYPO3 installation. Then run the following command
typo3 cacheflow:process
The initial run will flow all existing pages, so will take some minutes. After this only the relevant pages are flowed.

See also Run a command from the command line for further explanation of TYPO3 console commands.
Options
--
(optional): Specifies the number of pages per execution. If nothing is set, the default value is 50.
Scheduler Task
After you are familiar with the usage, you can create a Scheduler task, adapt the batch size to the performance of your server and execute the task every minute (with no parallel execution allowed).
Check the TYPO3 manual for Adding or editing a task
Dashboard widget
System maintainers can keep an overview by adding a prepared dashboard widget to the TYPO3 backend.
Just use the wizard to add the widget Cache
.

More on Adding Dashboard