Click Create and Select the Blank app after that selected the Blank Canvas app-> click Phone -> select Save -> select New Screen
Create one new Text label -> click Insert and select Text label->Rename the text label To file name as shown in the screenshot.
Click Insert -> select Text Input -> Select Textbox for get file name from user We can set a Textbox default value, I am leaving the default value is empty.
Same as above two steps take one text label and Text input for file Content.
Click insert->Choose button and place button the Screen
Change the button Name -> Properties -> Text
We Created the one SharePoint Document Library in the SharePoint
Then click on powerAutomate->create a flow
Create New flow->Connect SharePoint->Create file
Choose Site collection->Chose Document Library from site collection
integrating with PowerApps->click on Ask in PowerApps