You can use programming language and automate those APIs. You can create your own scheduler and call the APIs at specific interval of time.

For example, in Java you can use Java scheduler to schedule and automate the call triggering.

Or you can write the API code in a language like PHP or Python and have a CRON trigger the code every X hours, or X days. You would need to configure the API with a specific "task" like SMS would look like this in PHP:

$apiResponse = $sdk->platform()->post('/account/~/extension/~/sms',
array('from' => array('phoneNumber' => $from),
'to' => array( array('phoneNumber' => $to) ),
'text' => $message ) );

You can do it in a loop of numbers and count the number of loopings so that you don't go over any limits, and set the time on the CRON to also not trigger so often that it exceeds any limitations. You also have to configure your RingCentral App to use the SMS and Fax portions of the API.