You need to create Microsoft Teams app from a canvas app. You download zip with your app and want to upload it as a custom app to the Teams. But you don`t see the "Upload a custom app" option on the Teams Apps screen. 
What two steps should the Teams administrator do that would help you upload your zip?

Answer options:

A.Add App Studio to Teams
B.Enable Upload custom apps
C.Pin your app in the Teams navigation bar
D.Create a custom app policy
E.Add Power Apps to Teams

Correct Answers: B and D 
You can add or embed Power Apps apps into Microsoft Teams. There are two ways to embed an app: as a tab app or a personal app. Both types of apps, model-driven and canvas, can be added to the Teams as a tab app. But only the canvas app can be embedded as a Teams (personal) app. 
To make a Teams app from a canvas app, you need to export your canvas app in a zip file using the "Add to Teams" function in the Power Apps portal. Then you can upload the zip file to Teams by clicking on the "Upload a custom app" button on the left bottom of the Teams App panel. 
If you don’t see this item, you need to ask the Teams administrator to create a new Custom app policy and enable the “Upload custom apps” option. Admin can do both these steps in Microsoft Teams admin center under Teams Apps/Setup policies section. Admin needs to create a new app setup policy (Number 1) and allow the custom apps upload (Number 2). The Upload of custom apps is also called “side loading.” This approach helps users to run the Teams apps without uploading to the Teams app store. 

Then you can open Teams Apps and select the “Upload a custom app” option on the left bottom of the panel (Number 1). Teams will ask for the zip file and install your app. 
If you are an admin, you can publish an app to Microsoft Teams catalog (Number 2). 

All other options are incorrect. 
For more information about Power Platform integration with Microsoft Teams, please visit the below URL: 

https://docs.microsoft.com/en-us/powerapps/teams/embed-teams-app