Through this blog, you can create a PowerApp based on a SharePoint list
Source data from a SharePoint list
Create the PowerApp
Browse go to: https://make.powerapps.com/ and choose SharePoint.
Connect to a SharePoint list
In this example: Staff Events
Press skip. You will soon see a working 'list' of basic functionality. If you press preview at the top you can test this application.
Publishing the application
You can publish this application via: file Save.
Choose a Name + Icon + Background Color
Share the application with other people
Choose with whom you wish to share this application
Adding the PowerApp to Microsoft Teams
Upload your app to Teams; Go to the Apps page in Teams where you will find an option for uploading a custom app. Upload the ZIP file of your app and follow the prompts.
If you cannot upload a custom app yourself, send the ZIP file to your Teams administrator. Learn more
Navigate to the desired Team
Select Power Apps
Choose the desired application.
Your application is now visible in Teams. Be sure to set the necessary permissions for other users!