There is actually a "guest" feature in Slack (for business). I imagine yours would be the intended use case. More info: https://get.slack.help/hc/en-us/articles/202518103-Multi-Cha...
There is actually a "guest" feature in Slack (for business). I imagine yours would be the intended use case. More info: https://get.slack.help/hc/en-us/articles/202518103-Multi-Cha...