Update Checkout Extension Header Icon

I’m trying to use a custom image for the checkout header icon:

Using the admin api, the docs are saying to target this field:

Here is my mutation:

mutation changeBrandingHeader($checkoutBranding: CheckoutBrandingInput!, $checkoutProfileId: ID!) {
checkoutBrandingUpsert(checkoutBrandingInput: $checkoutBranding, checkoutProfileId: $checkoutProfileId) {
checkoutBranding {
customizations {
header {
cartLink {
image {
url
}
}
}
}
}
userErrors {
field
message
}
}
}

Variables:

{
“checkoutProfileId”: “gid://shopify/CheckoutProfile/--------”,
“checkoutBranding”: {
“customizations”: {
“header”: {
“cartLink”: {
“image”: {
“url”: “https://cdn.shopify.com/s/files/1/0578/4947/9242/files/solid-cart-shopping-circle-arrow-left.jpg?v=1714072128
}
}
}
}
}
}

However, I am receiving a response saying the field does not exist:

“message”: “Variable $checkoutBranding of type CheckoutBrandingInput! was provided invalid value for customizations.header.cartLink.image.url (Field is not defined on CheckoutBrandingImageInput)”

Changing the contentType to “IMAGE” works just fine, as well as “TEXT” or “ICON”, but I can not access the url field for the image. I have tried to set several other fields inside the image object and nothing is working. We are using the 2024-04 api version.

I was using the wrong key to set the image. It needs to be “mediaImageId” and the variable is a GID that you need to find for the image:

"header": {
        "cartLink": {
            "contentType": "IMAGE",
            "image": {
                "mediaImageId": "gid://shopify/MediaImage/23455366643786"
            }
        }
      }