Your FTP details can be easily found by opening Hosting → Manage:
And scrolling down to FTP Accounts section:
There you will be able to see your FTP details:
FTP password
FTP password is not displayed in the control panel due to security reasons. FTP password is created for the domain either via onboarding, when you’re initially setting up the plan, or when you add an addon domain.
If you are not sure what password was set, you can change it through FTP Accounts → Change account password:
FTP password also applies for SSH connections.
NOTE:
One FTP account is always created by default once you finish setting up your hosting.