Policyfile.lock file upload error

After running chef install and chef update command I got my policyfile.lock.json generated, when I upload the policyfile.lock to chef server i'm getting the below error.

[2019-08-21T14:12:07+08:00] WARN: Failed to read the private key testuser1.pem: #<Errno::ENOENT: No such file or directory @ rb_sysopen - testuser1.pem>
Error: Failed to upload policy to policy group staging
Reason: (Chef::Exceptions::PrivateKeyMissing) I cannot read testuser1.pem, which you told me to use to sign requests!

Does the pem file exist in your c:\chef or etc/chef folder or the path specified in your client.rb for validation_key?

Issue solved by adding .pem file in my cookbook directory! thank you