WeChat.BatchSends.batch_send_by_tag

You're seeing just the function batch_send_by_tag, go back to WeChat.BatchSends module for more information.
Link to this function

batch_send_by_tag(client, batch_send_by_tag_body)

Specs

根据标签进行群发【订阅号与服务号认证后均可用】 - 官方文档