Microsoft Teams is available on Ubuntu / KDE Neon as an Electron app: https://teams.microsoft.com/

Unfortunately, the system tray icons don't look nice in the Breeze / Breeze Dark theme (see e.g. https://blog.microlinux.fr/wp-content/uploads/2020/05/ms-teams-statut.png)

A good starting point could be those two SVGs:
- https://www.svgrepo.com/svg/306419/microsoftteams
- https://www.svgrepo.com/svg/303180/microsoft-teams-logo

Note that there should be at least two variants: "Normal" (like in the screenshot) and "With unread notification" (with a red bell icon in the bottom right of the Teams icon).