Hi @john john ,
As far as I know, you can try to use the SharePoint client object model (CSOM) to retrieve, update, and manage data in SharePoint. I recommend you can refer to this document: Using CSOM for .NET Standard instead of CSOM for .NET Framework
Since we have limited knowledge of Power Apps, if you would like to know about developing with Power Apps, I suggest you can open a new thread in the forum below, more professional will help you.
Power Apps: https://powerusers.microsoft.com/t5/Power-Apps-Community/ct-p/PowerApps1
Hope it can help you. Thanks for your understanding.
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