Auth Error

So, Instagram changed their API today, I forgot about one site, now when I click the button to Login and get my Access Token, I get the following error after logging into the client’s Instagram account.

{
code: 403,
error_type: “OAuthForbiddenException”,
error_message: “You are not a sandbox user of this client”
}

Not sure where to go from here.

https://wordpress.org/plugins/feed-them-social/