hi I am trying pulumi crossguard for first time i am getting below error error: no Pulumi.yaml project file found

steps:
mkdir policypack && cd policypack
pulumi policy new aws-python
pulumi preview --policy-pack <path-to-policy-pack-directory>

The

pulumi preview ...

command needs to be run from the directory where your Pulumi application resides, not from where the policy pack code is. So you likely just need to

cd ..

and then run the preview command again.