Error logging into external app from Teams

[John_R007]

I'm trying to enable the 3rd party app Slido for our Teams.  The app has been whitelisted and I can add it to a meeting, but when I try to activate it, it disallows logging in to the app with the error message: Unable to load app outside of Microsoft Teams

I inherited this environment, not sure what other policies may have been put in place that may be blocking it.  Can anybody steer me in the right direction?

TIA

JohnR

[#2]

@John_R007 Hi, I have no experience from this app but being available in the store I would walk through these settings.

Manage app policies in Teams - Microsoft Teams | Microsoft Docs

[#3]

@ChristianJBergstrom Thanks, Ya, I did work through that doc which got me to where I am.  I have it in the allowed 3rd party apps list but I still seem to be missing a policy somewhere.

[#4]

Have you also verified that the policies are assigned to your user/s? Try reaching out to the app developer too. Surely they must have a support that has encountered this before.