Pdf showing app from firebase

I need an app which show pdf file from firebase in my app
I need two option there one online mode and download mode
When user click on online mode the pdf file from firebase oprn in online mode in the app
And when user click on download mode than the pdf download in the app and download button change to read offline
Note- pdf should download via app only not via chrome
And after download there is delete option also when user download it
Take idea from images i upload
I need code also

Note --Code should be in kotlin no java or any other only kotlin