Magento – How to override webapi.xml in custom module

I want to override /vendor/magento/module-catalog/etc/webapi.xml file in my custom module.

<route url="/V1/categories" method="GET">
        <service class="Magento\Catalog\Api\CategoryManagementInterface" method="getTree" />
        <resources>
            <resource ref="Magento_Catalog::categories" />
        </resources>
    </route>

My module path for this webapi is
/app/code/CustomModule/Catalog/etc/webapi.xml

I want to override this specific code.

 <!-- Category Product Links -->
    <route url="/V1/categories/:categoryId/products" method="GET">
        <service class="Magento\Catalog\Api\CategoryLinkManagementInterface" method="getAssignedProducts" />
        <resources>
            <resource ref="anonymous" />
        </resources>
    </route>

I tried but it still gives me error

{
    "message": "Consumer is not authorized to access %resources",
    "parameters": {
        "resources": "Magento_Catalog::categories, anonymous"
    },
    "trace": "#0 /var/www/html/rb-dev/vendor/magento/
webapi/Controller/Rest/RequestValidator.php(68): 

Magento\Webapi\Controller\Rest\RequestValidator->checkPermissions()\n#1
/var/www/html/rb-dev/vendor/magento/module-webapi/Controller/Rest/InputParamsResolver.php(86):
Magento\Webapi\Controller\Rest\RequestValidator->validate()\n#2
/var/www/html/rb-dev/vendor/magento/module-webapi/Controller/Rest.php(322):
Magento\Webapi\Controller\Rest\InputParamsResolver->resolve()\n#3
/var/www/html/rb-dev/vendor/magento/module-webapi/Controller/Rest.php(239):
Magento\Webapi\Controller\Rest->processApiRequest()\n#4
/var/www/html/rb-dev/vendor/magento/framework/Interception/Interceptor.php(58):
Magento\Webapi\Controller\Rest->dispatch(Object(Magento\Framework\App\Request\Http))\n#5
/var/www/html/rb-dev/vendor/magento/framework/Interception/Interceptor.php(138):
Magento\Webapi\Controller\Rest\Interceptor->___callParent('dispatch',
Array)\n#6
/var/www/html/rb-dev/vendor/magento/framework/Interception/Interceptor.php(153):
Magento\Webapi\Controller\Rest\Interceptor->Magento\Framework\Interception\{closure}(Object(Magento\Framework\App\Request\Http))\n#7
/var/www/html/rb-dev/generated/code/Magento/Webapi/Controller/Rest/Interceptor.php(39):
Magento\Webapi\Controller\Rest\Interceptor->___callPlugins('dispatch',
Array, Array)\n#8
/var/www/html/rb-dev/vendor/magento/framework/App/Http.php(135):
Magento\Webapi\Controller\Rest\Interceptor->dispatch(Object(Magento\Framework\App\Request\Http))\n#9
/var/www/html/rb-dev/generated/code/Magento/Framework/App/Http/Interceptor.php(24):
Magento\Framework\App\Http->launch()\n#10
/var/www/html/rb-dev/vendor/magento/framework/App/Bootstrap.php(256):
Magento\Framework\App\Http\Interceptor->launch()\n#11
/var/www/html/rb-dev/index.php(39):
Magento\Framework\App\Bootstrap->run(Object(Magento\Framework\App\Http\Interceptor))\n#12
{main}" }