Can't get my restful sensor to work

Configuration
1

I created this RESTful sensor:

sensor:
   - platform: rest
     resource: "http://192.168.1.84/ipcontrol/v1/groups/current/sources/"
     method: GET
     name: "devialet AUX"
     value_template: "{{ value_json.sources[0] }}"

this API returns a list like this:

{
    "sources": [{
        "deviceId": "c803cc3b-647f-5d95-b712-b867abe80181",
        "sourceId": "f4a7f06a-da1d-4fc7-b341-39a702969ca4",
        "type": "upnp"
    }, {
        "deviceId": "19ee4eeb-1ed0-5b20-b834-6d66a2bf4acc",
        "sourceId": "549ad3aa-3e5f-4905-80c7-dc182ba040d0",
        "streamLockAvailable": false,
        "type": "opticaljack"
    }, {
        "deviceId": "c803cc3b-647f-5d95-b712-b867abe80181",
        "sourceId": "5789cce5-8ab6-4832-9b10-514be4b86fe5",
        "streamLockAvailable": true,
        "type": "opticaljack"
    }, {
        "deviceId": "c803cc3b-647f-5d95-b712-b867abe80181",
        "sourceId": "dfa269e5-ce7f-4b79-85d3-90826a4a040b",
        "type": "spotifyconnect"
    }]
}

On every reboot of the API device, the order of this list changes and the value of the sourceId field changes for each device.
My goal is to get the sourceId for the devices with “type”: “opticaljack” AND “streamLockAvailable”: false.

How can I extract the correct item, and consequently the value of sourceId and set that as a state for the sensor? I want to use this as an input to an automation afterwards.

I’ve tried to cobble together some code that does not function and is not compliant:

    value_template: >
       {% set c = value_json.sources | selectattr('type', 'eq', 'opticaljack' | 'streamLockAvailable', 'eq',  false) | first | default %}
       {% if c.type == 'opticaljack' and c.streamLockAvailable == false  %}
          {{ c.selectattr('sourceId') }}
       {% endif %}

Thanks for your input.