GET request to them, for example with curl. They enable you to call a check from a CI/CD pipeline, a bash shell or programmatically in your code. No API key is needed, as the token in the URL authorizes the call. Trigger URLs are separate from the checkly trigger CLI command.
You can specify command line triggers as standalone resources at check or group level:
url and token contain a secret token, so the Checkly provider marks them as sensitive and Terraform requires any output that references them to set sensitive = true. Sensitive outputs are hidden in terraform plan and terraform apply output; read the value with terraform output -raw test-trigger-check-url.
You can see all the configuration options for group triggers, as well as more examples check triggers, on the official Terraform registry documentation page.