*-a* [ATTACHMENT [ATTACHMENT ...]], *--attachment* [ATTACHMENT [ATTACHMENT ...]]::
Add one or more files as attachment.
+Can be either a file path or a data URI. Data URI encoded attachments must follow the RFC 2397.
+Additionally a file name can be added:
+e.g.: `data:<MIME-TYPE>;filename=<FILENAME>;base64,<BASE64 ENCODED DATA>`
*--sticker* STICKER::
Send a sticker of a locally known sticker pack (syntax: stickerPackId:stickerId).