How to make mandatory in child doctype

I tried this, how to make mandatory in child doctype, and it doesn’t work

frappe.ui.form.on('Quotation Item', {
  sourcing_link: function (frm, cdt, cdn) {
    var d = locals[cdt][cdn];
    msgprint("Hey there");
    frm.set_df_property('sourcing_link2', 'reqd',1);
  }
});

It works on Parent Doctype

frm.set_df_property('sourcing_link2', 'reqd',1);

Hi refer below link,
[Tutorial] set_df_property for child table fields?

Try it:
frm.get_field(“your_table_name”).grid.fields_map[“your_field_name”].reqd =1
refresh_field(“your_table_name”);

You can also try this:

frappe.meta.get_docfield('Journal Entry Account', "party", frm.doc.name).reqd = 1;