This page explains how to send videos within a chat.
iPhone
1. Open the default Photos app
2. Select the video you want to send and tap the share symbol in the lower left corner.
3. Tap "Save to Files"
4. Select a destination and tap "Save"
5. Open the corresponding chat in the KANNA App
6. Tap the document icon in the lower left corner
7. Select a video file from "Select Document"
8. Tap [Add] to complete the upload
Android
1. select the chat you want to send the video to and tap the document icon in the lower left corner
2. Select a video file from "Select Document" and tap "Add"
3. Upload Completed
PC Version
1. Select the chat you want to send the video to and click the document icon in the lower left corner
2. Select the file and click "Send"
3. Upload Completed
There is also a video, so please check it out.