frappe.ui.form.on("Quotation", {
    party_name: function(frm) {
        setTimeout(function() {
            if (!frm.doc.tax_category){
                frappe.call({
                    method: "csf_tz.custom_api.get_tax_category",
                    args: {
                        doc_type: frm.doc.doctype,
                        company: frm.doc.company,
                    },
                    callback: function(r) {
                        if(!r.exc) {
                            frm.set_value("tax_category", r.message);
                            frm.trigger("tax_category");
                        }
                    }
                });           
        }
          }, 1000);   
    },
});