Magento 2 Call Rest api issue : "\"%fieldName\" is required. Enter and try again.",

Question

I am trying to call Magento 2 Quote rest api,

 <route url="/V1/carts/mine/coupons/:couponCode" method="PUT">
        <service class="Magento\Quote\Api\CouponManagementInterface" method="set"/>
        <resources>
            <resource ref="self" />
        </resources>
        <data>
            <parameter name="cartId" force="true">%cart_id%</parameter>
        </data>
    </route>

but i get issue like "\"%fieldName\" is required. Enter and try again.",

here is the screenshot.

Can any one help me to resolve this. Thanks

Answer 1

If using PUT /V1/carts/mine/coupons/:couponCode or GET /V1/carts/mine/coupons, we don't need to pass cart_id.

cart_id will be overridden by vendor/magento/module-quote/etc/di.xml

<type name="Magento\Webapi\Controller\Rest\ParamsOverrider">
    <arguments>
        <argument name="paramOverriders" xsi:type="array">
            <item name="%cart_id%" xsi:type="object">Magento\Quote\Model\Webapi\ParamOverriderCartId\Proxy</item>
        </argument>
    </arguments>
</type>

Note: try to change GET to PUT. You're using wrong method?