Find all drops of a manager account

Question

When i run the command :-

drops = Dropio::Drop.find_manager_drops(your_manager_api_token)

it throws an error "Invalid manager account or manager api token.".

Whenever i am taking manager api token from the following location:-

firstly login with proper credentials > Settings > Premium API Access

"Premium Api Access" provides two things:-
Your Premium Key: -----------
Your Manager Api Token: ----------