Hi @PA_NewUser ,
Do you want to loop the uploaded image data from your canvas app back to your SP Library?
Based on the needs that you mentioned, I afraid that PowerApps could not achieve your needs. Currently, there is no direct way to upload picture file from canvas app to SP Library.
As an alternative solution, I think the combination of Power Apps and Power Automate flow could achieve your needs. I assume that you list all your question records in a Gallery, and each question has a QuestionID.
Within your canvas app, you need to collect these captured images into a collection along with Picture name, and QuestionID. Then convert the collection table as a JSON String, then pass the JSON String to your flow. Within your Power Automate flow, convert the passed JSON String into a actual JSON table using json expression, then apply a "Apply to each" action to this converted JSON Table, within the "Apply to each" action, you could add a "Create file" action of SharePoint connector to create file based on the passed JSON string.
Within your canvas app, you could collect your image collection as below:

On your side, you may type the following formula:
Collect(
colPic,
{
PicContent: Substitute(JSON(UploadedImage1.Image, JSONFormat.IncludeBinaryData), """", ""),
PicName: ThisItem.QuestionID & "_" & AddMediaButton1.FileName
}
)
When you want to pass the colPic collection back to your flow, you need to try the following formula:
'Flow Name'.Run(JSON(colPic, JSONFormat.IncludeBinaryData))
Your flow's configuration may look like below:

Please check and see if the following video would help in your scenario:
https://www.youtube.com/watch?v=kQVYid1p_vA
https://www.youtube.com/watch?v=UYK7yruBHDM
https://www.youtube.com/watch?v=ZXWyDgDEHPo
Best regards,