You can share the following files as attachments on WebChat:
Documents
Photos
Videos
Attaching Documents
To attach documents:
Start a new chat, or open an existing conversation or group chat.
Click the attachment icon.

Click Document.

Choose the document which you want to attach.
(Optional) Add a caption or required text.
Click the Send icon.

The attachment is shared.
Attaching Photos or Videos
To attach a photo or a video:
Start a new chat, or open an existing conversation or group chat.
Click the attachment icon.

Click Photo or Video.

Choose the photo or video which you want to attach.
Click the Send icon.
The photo or video is shared.