By default Arrow Checkout is in English. If you want to change the language of the checkout of the checkout to be in sync with your store you can define the locale as part of the extraData. Currently Arrow Checkout is only available in English (by default) and Bahasa Indonesia. If you require any additional languages, please contact us via your Account Manager.

The locale can be defined as part of Arrow Init API within the extraData as can be seen below. Set locale to "id" to change Arrow Checkout language to Bahasa Indonesia:

"extraData" : {
  "locale": "id"