Snapchat "Device Restricted" Error Blocks Login

I purchased this phone from a friend, but I'm unable to use Snapchat. I keep getting a message that says "This device is restricted." I would greatly appreciate your assistance in helping me connect with my friends on Snapchat. I'm having trouble accessing my Snapchat account. I keep getting the "Device Restricted" warning. I would like to have this matter resolved. Every time I attempt to log into my account using my username and password, I'm unable to gain access and I'm greeted with a warning message that says "Device Restricted." I kindly request help and hope for a prompt resolution.