WhatsApp Web Limitation
Since this feature is not available on WhatsApp Web, Z-API currently does not support sending messages via broadcast lists. This is a limitation of the WhatsApp Web platform itself.
Broadcast list
As previously mentioned, for WhatsApp everything is treated as a chat, and broadcast lists are no different. Just like with groups, you can identify your broadcast lists through the get /chats method.
Broadcast lists have an identifier (ID/Phone) with the -broadcast suffix, for example: 1624901640-broadcast.
Additionally, unlike groups, interactions originating from broadcast lists occur individually. That is, when a recipient replies to a message sent via broadcast list, the reply will be received as an individual conversation, allowing direct interaction with the contact.