Dataflow runner currently supports Python versions ['3.6', '3.7', '3.8'], got 3.9.2 (default, Feb 28 2021, 17:03:44)

I have problem with Google Cloud Shell Editor. When i tried run

    apache_beam.examples.wordcount \
    --region us-central1 --input \
    gs://dataflow-samples/shakespeare/kinglear.txt \
    --output \
    gs://<STORAGE_BUCKET>/results/output \
    --runner DataflowRunner \
    --project makara-things \
    --temp_location \
    gs://<STORAGE_BUCKET>/temp/

i got

ERROR: No matching distribution found for apache-beam==2.36.0
Exception: Dataflow runner currently supports Python versions ['3.6', '3.7', '3.8'], got 3.9.2 (default, Feb 28 2021, 17:03:44)
[GCC 10.2.1 20210110].
To ignore this requirement and start a job using an unsupported version of Python interpreter, pass --experiment use_unsupported_python_version pipeline option.

how can I downgrade python version in Google Cloud Shell?