In Slack, click the name of your server in the top left corner and browse to Administration > Customize. You will see the new Bulk Emoji Uploader at the top of the screen.

Slack pioneered emojis in the work chat, but it slacked off when it came to adding the latest emojis. If you can’t find an emoji that you like in Slack, or if you want to make things more fun ...

Once custom emoji are uploaded into Teams, they’ll only be visible within the same organization domain. Microsoft says that general availability for custom emoji is expected sometime this July.