All functions:
“Accounting”: “1”,
“Administrative”: “2”,
“Arts and Design”: “3”,
“Business Development”: “4”,
“Community and Social Services”: “5”,
“Consulting”: “6”,
“Education”: “7”,
“Engineering”: “8”,
“Entrepreneurship”: “9”,
“Finance”: “10”,
“Healthcare Services”: “11”,
“Human Resources”: “12”,
“Information Technology”: “13”,
“Legal”: “14”,
“Marketing”: “15”,
“Media and Communication”: “16”,
“Military and Protective Services”: “17”,
“Operations”: “18”,
“Product Management”: “19”,
“Program and Project Management”: “20”,
“Purchasing”: “21”,
“Quality Assurance”: “22”,
“Real Estate”: “23”,
“Research”: “24”,
“Sales”: “25”,
“Customer Success and Support”: “26”

Please make a job search on LinkedIn and choose your target function (i.e Infomation Technololy) and you’ll see the function_id in the address bar of your browser. In this case, function_id is ‘it’.