Add host to host collection with uri ansible module

I'm working wit uri ansible module with satellite.
I did one playbook to create a new host_collection and it works OK.

• name: CREATE HC
  uri:
  url: "https://xxxxxx/katello/api/host_collections/"
  user: "{{user}}"
  password: "{{password}}"
  method: POST
  return_content: yes
  force_basic_auth: yes
  validate_certs: no
  body_format: json
  body: '{"name":"{{hc}}","organization_id":"1"}'
  status_code: [200,201,202]

But I want to do a playbook to add/remove host from a host collection.

The api guide indicates use

PUT /katello/api/v2/host_collections/:id/add_systems

• name: Assign sat server to host_collection
  uri:

  url: "https://xxxxxx/katello/api/host_collections/586/add_hosts/"
  user: "{{user}}"
  password: "{{password}}"
  method: PUT
  return_content: yes
  force_basic_auth: yes
  validate_certs: no
  body_format: json
  body: '{"hosts_ids":"[1280]"}'
  status_code: [200,201,202,204,301,401]

But it doesn´t work.

"json": {
    "displayMessage": "undefined method `map' for nil:NilClass\nDid you mean?  tap", 
    "errors": [
        "undefined method `map' for nil:NilClass\nDid you mean?  tap"
    ]
}, 

The json with the array is badly built?