Assuming you are using Pandora FMS 6.0, the steps are:
1. Create the [Alert command](http://wiki.pandorafms.com/index.php?title=Pandora:Documentation_en:Alerts#The_Alert_Command_.28Pandora_Versions_5_and_above_only.29) in Pandora FMS console following the instructions of your solution inside this folder
2. Define the [Alert Action](http://wiki.pandorafms.com/index.php?title=Pandora:Documentation_en:Alerts#Alert_Actions_.28all_Pandora_FMS_versions_including_5.0.29) in Pandora FMS console following the instructions of your solution inside this folder
3. Assign the action to an existing module under Alerts -> [List of alerts](http://wiki.pandorafms.com/index.php?title=Pandora:Documentation_en:Alerts#Assigning_Alerts_from_an_Alert.27s_Sub_Menu):
![assign template to module](help/images/3-assign-template-to-module.png?raw=true "Assign a template to a module")
4. Optinionally, go to your agent and verify the alert has been created:
![Verify the alert creation](help/images/4-verify.png?raw=true "Verify the alert creation")
When the alert triggers, the result would be something like this:
![Mattermost-real-example](help/images/5-mattermost-result.png?raw=true "Mattermost real example")