how to create and run DAG in Airflow 2?

[Alexander Mikhaylov]

Hi, I've tried to create a simple DAG with Airflow 2 and launch it, with a 
program like this -

-----
import os

# with open('../airflow/dags/uniqueId14.py', 'w') as fp:
#     fcont = """

from datetime import datetime, timedelta
from airflow import DAG
from airflow.operators.bash import BashOperator

with DAG(
    dag_id='uniqueId15',
    default_args={
        'depends_on_past': False,
        'email': ['airf...@example.com'],
        'email_on_failure': False,
        'email_on_retry': False,
        'retries': 1,
        'retry_delay': timedelta(minutes=5),
    },
    description='A simple tutorial DAG',
    schedule_interval=timedelta(days=1),
    start_date=datetime(2022, 4, 11),
    catchup=False,
    tags=['example'],
) as dag:

    t1 = BashOperator(
        task_id='print_date',
        bash_command='date',
    )

    t2 = BashOperator(
        task_id='sleep',
        depends_on_past=False,
        bash_command='sleep 5',
        retries=3,
    )

    t1 >> t2

    globals()["uniqueId15"] = dag
# """
#     fp.write(fcont)

os.system('airflow dags trigger uniqueId15')
-----

I've also tried to save the content of DAG file into Airflow dags folder. In 
both cases the last command, to launch the DAG, returns something like

airflow.exceptions.DagNotFound: Dag id uniqueId15 not found in DagModel

Can it be done? If yes, how?

Thanks,

Alex