In case you haven't configured your email account on your iDevice correctly, you might encounter this error message. Some of Termius's features, such as key import, may require an email account. This email account is configured in the settings of your device.
To do so,
- Navigate to
Mail, Contacts, Calendars
! Note that an email account is set up, not in Termius but in the settings of your device
See Apple Support for more information.