Triggers is the correct option.

Triggers are the automation component that monitor the events users choose and start rule execution. They listen for events such as issue created, issue updated, comment added, or scheduled times and when a configured event occurs they kick off the rule so the system can evaluate Conditions and then run Actions.

Conditions are evaluated after a Triggers event fires to decide whether the rule continues. They do not observe events or begin rule execution.

Webhooks are an external mechanism that can send events into the system but they are not the automation component that monitors chosen events and starts a rule. Webhook calls can feed a Triggers type but Webhooks themselves are not the rule starter.

Actions perform the work that changes issues sends notifications or updates fields after a rule has started. They do not monitor for events and they do not start rule execution.

Requirements is not a standard automation component that watches for events. The term might refer to preconditions for a rule but it does not act as the event listener that starts the rule.

Steps is a generic term for parts of a rule and it does not specifically refer to the event listener. Rules are built from a trigger plus conditions and actions which together form the steps but the listener role belongs to Triggers.

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