How to add Today and Clear button in calendar

where is the myCal.showToday(); function that was in version 5
How do I add the “Today and Clear” button in version 7?
cal

where is the myCal.showToday(); function that was in version 5

Please, try to use the showDate() method:
https://docs.dhtmlx.com/suite/calendar/api/calendar_showdate_method/

How do I add the “Today and Clear” button in version 7?

Unfortunately it is not available to add the custom controls to the calendar object itself.
You may attach your calendar to a pop up or a container together with the needed custom controls.
Something like:
https://snippet.dhtmlx.com/a4br8b06