Using standard erpnext python function on custom button

ERPNext
1

In Job Card doctype I have added one button and on click of it I want to trigger one python function from erpnext source code. To explain it more, I want to call validate_sequence_id(self) function which is part of job_card.py when a new button is clicked.

2

you can use this syntex

refresh:frm => {
    frm.add_custom_button(__('<New Button>'), () => {
		frappe.call({
            method:"erpnext.manufacturing.doctype.job_card.job_card.[ whitelisted function name ]",
            arg:{
                
            }
        })
	})
}