URL host name is not generated properly in self link with serializer

I sometime use the serializer to render the reply from some API request like below.
In controller

    result = Hoge.find(1)
    resource = Object.const_get('HogeResource')
    serializer = JSONAPI::ResourceSerializer.new('HogeResource')
    body = serializer.serialize_to_hash(resource.new(result, nil))
    render json: body, status: 20

and the result is
http://localhost:3000/hoges/1

{
  "data": {
    "id": "1",
    "type": "hoges",
    "links": {
      "self": "/hoges/1"
    },
    "attributes": {

self should have the hostname like http://localhost:3000/amc/hoges/1

Any idea how to fix this?

Reproduce the controller example with JSONAPI::ResourceSerializer and inspect how it builds the resource's self link. Verify the serialized link includes the request hostname and the /amc path, then add or update coverage for the expected absolute URL.