Path parameter in url

Custom Apps
1

I am passing parameter:

"url": "/customers/{{parameters.customerId}}/carts",      // Relative to base URL
"method": "GET",
"headers": {},                          // Additional HTTP headers
"qs": {//"customerId":"DE--5"
},
"body":{
          // "{{...}}": "{{omit(parameters, 'customersId')}}"
}   ,                            // Query string

// Response handling
"response": {
	"output": "{{body}}"

but I am getting error in the response:

{
    "type": "error",
    "array": "[406 Not acceptable.]",
    "_engineData": {
        "calledAt": "Not available"
    }
}

the make curl seems to run properly in postman is there issue with my parameter ,my customer id is like “DE–5”:

{
		"name": "customerId",
		"type": "uuid" //I am also putting string and text as type
		"label": "customerId",  
		"required": true     
}