Google ads rest api cannot create a campaign "MUTATE_ACTION_NOT_PERMITTED_FOR_CLIENT" - google-ads-api

Question

I'm trying to create Google Ads campaigns using the Google Adwords API and getting this error MUTATE_ACTION_NOT_PERMITTED_FOR_CLIENT
I'm calling this endpoint:
https://googleads.googleapis.com/v10/customers/customerID/campaigns:mutate
with the payload:
{
"operations": [
{
"create": {
"status": "PAUSED",
"advertisingChannelType": "SEARCH",
"advertisingChannelSubType": "SEARCH_EXPRESS",
"paymentMode": "CONVERSIONS",
"name": "TestCampaign",
"campaignBudget": "customers/${customerID}/campaignBudgets/${budgetId}",
"biddingStrategyType": "COMMISSION",
}
}
]
}
Here is the response:
"errors": [
{
"errorCode": {
"operationAccessDeniedError": "MUTATE_ACTION_NOT_PERMITTED_FOR_CLIENT"
},
"message": "A mutate action is not allowed on this resource, from this client.",
"trigger": {
"stringValue": ""
},
"location": {
"fieldPathElements": [
{
"fieldName": "operations",
"index": 0
},
{
"fieldName": "create"
},
{
"fieldName": "advertising_channel_sub_type"
}
]
}
},
{
"errorCode": {
"operationAccessDeniedError": "OPERATION_NOT_PERMITTED_FOR_CAMPAIGN_TYPE"
},
"message": "This operation is not permitted on this campaign type",
"trigger": {
"stringValue": "SEARCH(SEARCH_EXPRESS)"
},
"location": {
"fieldPathElements": [
{
"fieldName": "operations",
"index": 0
},
{
"fieldName": "create"
},
{
"fieldName": "payment_mode"
}
]
}
}
],