This article tells how to send your API documentation to your MailBox
Step 1. Login to your MailboxLayer Account
Go to https://mailboxlayer.com/ and do login or Create MailboxLayer Account if you don’t have
Step 2. After Login You will get API Key - Copy the API Key
Step 3. Input Token
Go to Setup click more Menu then choose Developer Configuration
Step 4. Validation and Input Token
Go to tab MailBox layer then set 'Yes' and input the API Token you get