ISPmanager control panel allows you to create scheduled tasks - Cron. When logged in as a user, go to Main - Scheduler, as root - System - Scheduler.
To add a new task, click the New button, to edit an existing task - Edit.

Then fill in all fields in the window that opens.
Command - the path to the executable program.
The frequency is configured in basic or expert mode.
When setting the frequency in basic mode, select one of the options from the drop-down list:

Every hour - the task will be executed at the beginning of every hour, Daily - at the beginning of every day, etc.
In expert mode, the following format is used:
* - completing the task every minute,
*/n - task execution every n minutes (n from 0 to 59),
n - task execution with the beginning of the n-th minute,
a,b,c - execution of the task with the beginning of the specified minutes.
By analogy, a schedule is configured for other time parameters - hours (from 0 to 23), days (from 0 to 31), months (from 0 to 12). When specifying the day of the week, the following format is used: 0 - Sunday, 6 - Saturday.
For example, to run the task every 10 minutes, enter:

To run a php script, first specify the path to the interpreter.
For example, to run the test-script.php script daily at 06:10, enter:

The Description field is optional. But it is recommended to indicate at least a summary of the scheduled tasks for the convenience of using the scheduler.
The e-mail address field is also optional. If necessary, you can enter your email address here and uncheck the box next to the Do not send report to e-mail box. So notifications about the completion of tasks will be sent to the specified mail.
If you still have questions, please create a ticket to technical support.