RFlink send MQTT (non JSON) to Home Assistant

Hi, I have built an RFlink (Arduino MEGA) with Wifi (ESP-01), that will send MQTT messages to Home Assistant, I followed this video (https://www.youtube.com/watch?v=oYfbEyzT-Gs&feature=youtu.be).
In Home Assistant, if I got to: Developer Tools / MQTT / Listen to a topic, set ‘/RFLink/msg’ and listen, I can see MQTT messages sent, here is one as an example:

Another example:
Another example:

As I will receive multiple MQTT messages, from various devices, how can I receive messages, separate them, and react to each individually please?
An example would be great, if possible please.

Kind regards.

For anyone else looking to do the same thing, I figured it out using templates within automation:

- alias: "RingBell"
    platform: mqtt
    topic: /RFLink/msg
    condition: template
    value_template: "{{ 'Keeloq' in trigger.payload }}"