Storefront API checkoutCompleteWithCreditCardV2 access denied

[VishalSatwara]

Hello,

I am working on an app builder app. For it I have create a store and with a public app that uses the Storefront GRAPHQL API. Shopify Payments is enabled with Test Mode on , using the Bogus payment gateway.

Now I am trying to use checkoutCompleteWithCreditCardV2 mutation for credit card test payment. I had fetched the vault id https://deposit.us.shopifycs.com/sessions 

 https://help.shopify.com/en/partners/dashboard/managing-stores/test-orders-in-dev-stores#testing-usi... 

{
"card": {
"number": "4242424242424242",
"exp_month": 12,
"exp_year": 2022,
"cvc": 123
}
}

Now I got vault id as 

{
"id": "east-810da884392267c3e664e575e00a638a"
}

But when I hit the mutation 

mutation checkoutCompleteWithCreditCardV2($checkoutId: ID!, $payment: CreditCardPaymentInputV2!) {
checkoutCompleteWithCreditCardV2(checkoutId: $checkoutId, payment: $payment) {
checkout {
id
}
checkoutUserErrors {
code
field
message
}
payment {
id
}
}
}

I got this response

{
"data": {
"checkoutCompleteWithCreditCardV2": null
},
"errors": [
{
"message": "CheckoutCompleteWithCreditCardV2 access denied",
"locations": [
{
"line": 2,
"column": 3
}
],
"path": [
"checkoutCompleteWithCreditCardV2"
]
}
]
}

I had followed the steps:

created checkout using : checkoutCreate => associateCustomerWithCheckout =>  checkoutShippingLineUpdate => checkoutShippingAddressUpdateV2 => to create a checkout with all required information. 

Please help me out to fix this issue. Or guide me with any proper example or link or resources or video or anything which helps.