"Verify Access Signing Certificate in Settings" in OCI when running curl REST calls

Those days I was trying to retrieve some OCI Json data using
REST calls via curl. However, even though I’ve set up an application and Client
ID and Secret accordingly, I was getting the error below:

{

 
“httpStatusCode” : 401,

 
“httpMessage” : “Unauthorized”,

 
“executionContextId” :
“005WAjCLgER1FgyN06YBUF0003so0000FI,0:1:1”,

 
“errorCode” :
“urn:oracle:cloud:errorcode:tas:unauthorized”,

 
“errorMessage” : “Invalid Bearer Token:
java.lang.Exception: Cannot obtain Certificate. Verify Access Signing
Certificate in Settings”

}

“Cannot obtain Certificate. Verify Access Signing
Certificate in Settings”

Than I realize that there is an option under “Identity
Cloud Service -> Default Settings” called “Access Signing
Certificate”. As IDCS can have multi-factor authentications, Active Direct
link, etc, you must enable this option in order to allow an application service
to bypass all those IDCS authentication using directly the Client ID and Client
Secret.

After enabling this option, everything worked.