@Anonymous ,
As I mentioned, the Attachment control does not allow more than one attachment to be uploaded concurrently. You can of course do more than that directly in SharePoint.
Your original screen shot showed a docx and a txt file, so were they uploaded from Power Apps or SharePoint?
I assume this is a new attachment control you have created? If so there is not reason it will only allow PDF - there is code to do this, but you would have to apply it.
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