Is anyway to update Delivery order status to ‘Ready for delivery’ or ‘delivered’ status from API
The status of these on an order is based on the fulfillments orders. You can see this on the docs Order - GraphQL Admin
Theres more information on how fulfillment orders work here Migrate to fulfillment orders
Graphql Api: fulfillmentCreate - GraphQL Admin
{
"fulfillment": {
"lineItemsByFulfillmentOrder": [
{
"fulfillmentOrderId": "gid://shopify/FulfillmentOrder/7287863574833",
"fulfillmentOrderLineItems": [
{
"id": "gid://shopify/FulfillmentOrderLineItem/15793206690097",
"quantity": 1
}
]
}
],
"notifyCustomer": false,
"trackingInfo": {
"number": "stcc00001"
}
}
}