How to change environment variable before django settings will be initialized?

I try to use this, but in fact settings var that was initialized in docker container doesn't change.

conftest.py

@pytest.hookimpl(tryfirst=True)
def pytest_load_initial_conftests(early_config, parser, args):
    os.environ["CH_BASE_OF_URL"] = 'https://api.cowho.com'

settings.py

CH_BASE_URL = os.environ.get('CH_BASE_OF_URL')

I tried to use pytest_configure. It doesn't work too. Just passing of settings fixture to the test doesn't work for me, because initialization of data appears after django_db_blocker.unblock() by signal and depends from settings variable too.

Start with the conftest.py pytest_load_initial_conftests hook and the settings.py environment lookup shown in the report. Reproduce the initialization order with pytest and django_db_blocker.unblock(), including the signal that creates data. Done means documenting or verifying a supported way to set the environment variable before Django settings and signal initialization.