Add AIRFLOW__WEBSERVER__SHOW_TRIGGER_FORM_IF_NO_PARAMS=True in .env.localrunner in config folder. If you are using airflow version >2.7 it requires this parameter.In earlier Airflow versions the Play button opened a dropdown menu with two options Trigger DAG and Trigger DAG w/ config. The Trigger DAG w/ config button allowed you to pass params to the DAG run even if no params were defined at the DAG level.