Unable to run a automated Script to Backup the VCSA .Failed to run a script which makes connection via API calls

Error:  A server error occurred: 'com.vmware.vapi.std.errors.unauthenticated': Unable to authenticate user (Server error id:
'vapi.security.authentication.invalid'). Check $Error[0].Exception.ServerError for more details.

ERROR:vmware.appliance.vapi.auth:Requested SSO authentication but SSO authentication module is not available

vami.log

2019-12-02T18:48:44.336 [50279]INFO:twisted:"127.0.0.1" - - [02/Dec/2019:10:48:44 +0000] "POST /api HTTP/1.1" 200 2783 "-" "vAPI http client"
2019-12-02T18:50:35.336 [50279]ERROR:vmware.appliance.vapi.auth:Could not parse HOK Token
Traceback (most recent call last):
  File "/usr/lib/applmgmt/vapi/py/vmware/appliance/vapi/auth.py", line 183, in authenticate
    token.validate()
  File "/usr/lib/applmgmt/lib/extensions/py/vmware/appliance/extensions/authentication/authentication_sso.py", line 529, in validate
    signing_chain = self.validate_certificate()
  File "/usr/lib/applmgmt/lib/extensions/py/vmware/appliance/extensions/authentication/authentication_sso.py", line 700, in validate_certificate
    'One or more certificates cannot be verified.')AuthenticationError: One or more certificates cannot be verified.
2019-12-02T18:50:35.336 [50279]INFO:twisted:"127.0.0.1" - - [02/Dec/2019:10:50:35 +0000] "POST /api HTTP/1.1" 200 339 "-" "vAPI http client"

Note: PSC had total of 7 STS certificate chain out of which STS of 2 PSC is valid and the rest of STS was stale 

Resolution :

• Ensure to backup the PSC and VCSA 
• Verify if there are any Stale STS certificates of the old PSC are listed 
• Removed the STS certificate chains of the unused PSC 
• Restart the services and PSC and the VCSA

We can refer to the below KB if the issue is not with Certificates 

https://kb.vmware.com/s/article/67483