Sideloading broken in `New Teams` web client

[Wajeed-msft]

Copied bug from: https://github.com/OfficeDev/TeamsFx/issues/10280

Details from original post: Describe the bug

App install dialog does not appear when New Teams toggle is enabled in web client

To Reproduce Steps to reproduce the behavior:

1. Enable try New Team toggle in Teams web client
2. Start debug session (F5)
3. This app cannot be found message.

Expected behavior App install dialog should appear in both classic and new clients

Screenshots

New Teams

Classic Teams

VS Code Extension Information (please complete the following information):

• OS: Windows
• Version: 5.2.0

Additional context

URL used to launch browser, https://teams.microsoft.com/l/app/535a9681-f598-49ab-b638-8b2f4a613a02?installAppPackage=true&webjoin=true

Document Details

⚠ Do not edit this section. It is required for learn.microsoft.com ➟ GitHub issue linking.

• ID: b743e43d-95cc-3d1e-b142-31a16369f97e
• Version Independent ID: b743e43d-95cc-3d1e-b142-31a16369f97e
• Content: Teams Toolkit Overview - Teams
• Content Source: msteams-platform/toolkit/teams-toolkit-fundamentals.md
• Service: msteams
• GitHub Login: @zyxiaoyuer
• Microsoft Alias: zhany

[microsoft-github-policy-service[bot]]

Hi Wajeed-msft! Thank you for bringing this issue to our attention. We will investigate and if we require further information we will reach out in one business day. Please use this link to escalate if you don't get replies.

Best regards, Teams Platform

[Prasad-MSFT]

Hi @garrytrinder - Thanks for raising the issue. We will check this and will update you shortly

[Prasad-MSFT]

@garrytrinder - We are able to repro this issue. We have raised a bug for the same. We will inform you once we get any further update from engineering team.

Thanks!