Getting The request specifies YAML override content but that is allowed only for dry run builds error

while trying to override the azure devops azure-pipelines.yml file using python script through azure devops sdk getting below error:
Error: azure.devops.exceptions.AzureDevOpsServiceError: The request specifies YAML override content but that is allowed only for dry run builds.
could you please have a look into this and provide the solution.

Note: using azure-devops-6.0.0b4 version.

Execution logs:

Traceback (most recent call last):
File "test_demo.py", line 120, in
response = client_p.run_pipeline(project=project, run_parameters=res, pipeline_id=x)
File "C:\Program Files\lib\site-packages\azure\devops\v6_0\pipelines\pipelines_client.py", line 241, in run_pipeline
content=content)
File "C:\Program Files\lib\site-packages\azure\devops\client.py", line 106, in _send
response = self._send_request(request=request, headers=headers, content=content, media_type=media_type)
File "C:\Program Files\lib\site-packages\azure\devops\client.py", line 69, in _send_request
self._handle_error(request, response)
File "C:\Program Files\lib\site-packages\azure\devops\client.py", line 272, in _handle_error
raise AzureDevOpsServiceError(wrapped_exception)
azure.devops.exceptions.AzureDevOpsServiceError: The request specifies YAML override content but that is allowed only for dry run builds.

Start with the run_pipeline call in test_demo.py and the request construction at pipelines_client.py line 241, using the reported azure-devops-6.0.0b4 behavior as context. Reproduce the request and determine how its YAML override content relates to the service's dry-run restriction; done means documenting the supported request shape or confirming a reproducible SDK defect.