Identify manual interaction trigger

Configuration
1

Hi, I have an automation that is triggered from a MQTT subscription.
The automation sets an input_number.
How can I differentiate the next (after setting the input_number) actions for:

  1. MQTT change
  2. Manual interaction in the frontend (input_number))

The automation:

 - id: set_vent_fan_slider
    alias: Set vent fan slider
    initial_state: True   
    trigger:
      platform: mqtt
      topic: 'vent/fanspeed_actual'
    action:
      service: input_number.set_value
      data_template:
        entity_id: input_number.vent_fan_speed
        value: "{{ trigger.payload }}"
     -NEXT ACTIONS