How to Add a New SFTP User in WPEngine
1. Log in to your WPEngine account, and navigate to the Sites page.
2. Under the desired site, select an environment (dev, stag, prod) - each set of SFTP credentials will only work for one environment.
3. Select the Users and SFTP section, and click on the SFTP users tab.
4. Click Create SFTP user.
5. Add a username - this will be automatically attached (Ex: environmentname-username)
6. Click Add SFTP user (a password will be generated automatically).