diff --git a/src/fpti.js b/src/fpti.js
index ed5bb54f..78727f0f 100644
--- a/src/fpti.js
+++ b/src/fpti.js
@@ -21,6 +21,7 @@ export const FPTI_KEY = {
   BUTTON_TYPE: ("button_type": "button_type"),
   BUTTON_VERSION: ("button_version": "button_version"),
   BUYER_COUNTRY: ("buyer_cntry": "buyer_cntry"),
+  CHECKOUT_APP: ("checkout_app": "checkout_app"),
   CHOSEN_FI_TYPE: ("chosen_fi_type": "chosen_fi_type"),
   CHOSEN_FUNDING: ("selected_payment_method": "selected_payment_method"),
   CLIENT_ID: ("client_id": "client_id"),