I want to use Fetion to send short messages to non-Fetion friends, but I can't find the interface for sending short messages.

Direct sending by mobile phone is not supported. You need to log in to the mobile client and open the Address Book menu. If you find a non-friend in your mobile phone, you can send a short message directly to the non-friend in the address book. Standard tariff.

Pc is much more convenient: after logging in, click on the white envelope at the bottom of the client to enter the dialog box in the "SMS" menu bar. After editing the short message, the receiver can directly input the mobile phone number of a non-friend, or add a contact to send it through the pc address book.