I do not see a scheduled_at on the invoice object.
Below is the sample invoice data from your API documentation, these are the only fields we are see as well:
{
“invoice”: {
“id”: “inv:0-ChD_YNSHr4E6FJDariEoAexample”,
“version”: 1,
“location_id”: “S8GWD5example”,
“order_id”: “IVbTFOMBAGigR3fQYXlRexample”,
“payment_requests”: [
{
“uid”: “b165ffb1-e406-4ad7-bff3-6c216example”,
“request_type”: “BALANCE”,
“due_date”: “2022-09-29”,
“tipping_enabled”: true,
“computed_amount_money”: {
“amount”: 5000,
“currency”: “USD”
},
“total_completed_amount_money”: {
“amount”: 0,
“currency”: “USD”
},
“reminders”: [
{
“uid”: “65338625-5512-4bc6-9c8b-636aBexample”,
“relative_scheduled_days”: -1,
“message”: “Your payment is due tomorrow.”,
“status”: “PENDING”
},
{
“uid”: “98d9c2b6-35a0-4392-ab5c-bb791example”,
“relative_scheduled_days”: 3,
“message”: “Your payment is overdue.”,
“status”: “PENDING”
}
],
“automatic_payment_source”: “NONE”
}
],
“primary_recipient”: {
“customer_id”: “PGN6M13PEMX0S3D81NCexample”,
“given_name”: “Jane”,
“family_name”: “Doe”,
“email_address”: “[email protected]”,
“phone_number”: “1-206-555-1234”
},
“invoice_number”: “99846825”,
“title”: “My Invoice Title”,
“public_url”: “Square”,
“next_payment_amount_money”: {
“amount”: 5000,
“currency”: “USD”
},
“status”: “UNPAID”,
“timezone”: “America/Los_Angeles”,
“created_at”: “2022-07-25T14:26:54Z”,
“updated_at”: “2022-07-25T14:29:02Z”,
“accepted_payment_methods”: {
“card”: true,
“square_gift_card”: true,
“bank_account”: false,
“buy_now_pay_later”: false,
“cash_app_pay”: false
},
“delivery_method”: “EMAIL”,
“sale_or_service_date”: “2022-08-24”,
“store_payment_method_enabled”: false
}
}