Custom fields calculations

Frappe Framework Custom Script
8

@Mute

try:

frappe.ui.form.on("Expense Claim Detail", "validate", function(frm, dt, dn) {
        var row = locals[dt][dn];
        frappe.model.set_value(dt, dn, "claim_amount", flt(row.qte * row.prix_unitaire));
        refresh_field("expenses");
});

put it as Expense Claim custom script