Magento 2 REST API on add to cart "quoteId" is required. Enter and try again

Question

When I try to add to card any item via REST API I get this error:

"{"message":"\"%fieldName\" is required. Enter and try again.","parameters":{"fieldName":"quoteId"}}"

First time I get the cart id calling this

"rest/V1/carts/mine"

than I call

"rest/V1/carts/mine/items"

with this data:

{
  "cartItem": {
    "sku": "24-WG080",
    "qty": 1,
    "quote_id": cartID
  }
}

Tried with cart-item, quoteId, quote_id and more...

I'm stuck, I have no ideea what is wrong, the documentation is wrong? https://devdocs.magento.com/guides/v2.4/rest/tutorials/orders/order-add-items.html

Enabed developer mode, and now I got this error in response:

"#0 [internal function]: Magento\Quote\Model\Quote\Item\Repository->save(Object(Magento\Quote\Model\Quote\Item))
#1 /home2/xxx/vendor/magento/module-webapi/Controller/Rest/SynchronousRequestProcessor.php(95): call_user_func_array(Array, Array)
#2 /home2/xxx/vendor/magento/module-webapi/Controller/Rest.php(188): Magento\Webapi\Controller\Rest\SynchronousRequestProcessor->process(Object(Magento\Framework\Webapi\Rest\Request\Proxy))
#3 /home2/xxx/vendor/magento/framework/Interception/Interceptor.php(58): Magento\Webapi\Controller\Rest->dispatch(Object(Magento\Framework\App\Request\Http))
#4 /home2/xxx/vendor/magento/framework/Interception/Interceptor.php(138): Magento\Webapi\Controller\Rest\Interceptor->___callParent('dispatch', Array)
#5 /home2/xxx/vendor/magento/framework/Interception/Interceptor.php(153): Magento\Webapi\Controller\Rest\Interceptor->Magento\Framework\Interception\{closure}(Object(Magento\Framework\App\Request\Http))
#6 /home2/xxx/generated/code/Magento/Webapi/Controller/Rest/Interceptor.php(23): Magento\Webapi\Controller\Rest\Interceptor->___callPlugins('dispatch', Array, Array)
#7 /home2/xxx/vendor/magento/framework/App/Http.php(116): Magento\Webapi\Controller\Rest\Interceptor->dispatch(Object(Magento\Framework\App\Request\Http))
#8 /home2/xxx/generated/code/Magento/Framework/App/Http/Interceptor.php(23): Magento\Framework\App\Http->launch()
#9 /home2/xxx/vendor/magento/framework/App/Bootstrap.php(264): Magento\Framework\App\Http\Interceptor->launch()
#10 /home2/xxx/pub/index.php(29): Magento\Framework\App\Bootstrap->run(Object(Magento\Framework\App\Http\Interceptor))
#11 {main}"

Answer 1

1. Create a request to create the empty cart POST

{{magento_api_url}}/rest/default/V1/guest-carts/

this will return a token which is the cart ID (e.g 'KZepbhhPiGORreBKqIRlMCywGDTyQtR4')

2. Use that cart ID in the request which adds an item to the cart POST

{{magento_api_url}}/rest/default/V1/guest-carts/KZepbhhPiGORreBKqIRlMCywGDTyQtR4/items

with the payload similar to what you see below (where quote_id is the key you previously used and the SKU is the SKU of the product you want to add):

{
    "cartItem": {
        "qty": 5,
        "sku": "24-UG06"
    }
}

Answer 2

Refer to the Below Reference.

https://devdocs.magento.com/guides/v2.4/rest/tutorials/orders/order-create-quote.html