1. Open the thread and click Reply or scroll to the reply box.
2. To upload a video directly (if permitted):
Click Attach files or Upload.
Select the video from your device.
Wait for it to finish uploading.
Choose Insert if prompted, then submit your reply.
3. If direct video uploads aren't allowed:
Upload the video to a supported file-hosting service.
Paste the share link into your reply. Some forums automatically embed supported video links.