If you need to attach a screenshot to open support ticket on your iOS device, simply follow these steps.
1) Open the ticket in question by tapping on it in "My Tickets" and then tap the paperclip icon in the bottom right left corner of your screen.
2) On the next screen click the "+" icon to add screenshots to your next message from your device. You can add more than one per message so no need to send multiple messages for each screenshot
3) Once a screenshot has been uploaded it will appear on the bottom bar with the "+" and "x" icons; when you have added all the screenshots you would like to send just tap the "x" to go back to typing your message; any screenshots that appeared on that bottom bar will be sent with your message when you tap "send".
NOTE: You will have to type something for the message to get the screenshots to send.