Add Custom Field in POS

Is there any way to add custom field in POS using a custom app without breaking the update ?

You can try with make control

var patient = frappe.ui.form.make_control({
parent: page.main.find(“.patient”),
df: {
fieldtype: “Link”,
options: “Patient”,
fieldname: “patient”,
change: function(){
page.main.find(“.frappe-list”).html(“”);
draw_page(patient.get_value(), me);
}
},
only_input: true,
});