Answer:

To use HTTP POST can meet special needs in your scripts.
Switching from GET method to POST method is easy in EasyCron. you just need to change "HTTP method" field to "POST", and add param-value pairs to the "Send data" field while creating cron job. E.g. param1=value1&param2=value2.
When the cron job runs, the param-value pairs will be sent to the URL you specified. So the scripts on your server can process these POST values as they want.