Paypal invalid_token error

[DeveloperAcc]

Hi, I'm a developer and I'm using Paypal Subscription API code via cURL request. But I'm unable to complete this because of an error occurred while fetching information from my account into my site. Here is the code please check and if anyone can help me out here: *{"error":"invalid_token","error_description":"Token signature verification failed"}* Although the Token is same from my account not adding any invalid token.

[FinFren]

Has anyone been able to figure out why this is happening?