Ocelot API Gateway Optional Parameter

Is there a way to tell Ocelot that a parameter is optional?

Let's say the query param below is optional:

"DownstreamPathTemplate": "/api/SearchAPI/?query={query}",
"DownstreamScheme": "https",
"DownstreamHostAndPorts": [
    {
        "Host": "localhost",
        "Port": 5000
    }
],
"UpstreamPathTemplate": "/api/SearchAPI/?query={query}",
"UpstreamHttpMethod": [ "GET" ],
"FileCacheOptions": {
    "TtlSeconds": 60
}

If I send a request to /SearchAPI/?query= I get a 404 as response. I need to duplicate the Upstream to not use the param to fix. Is there another way to fix that?