Exporting Data Frame Extent to PNG

I’ve been trying to export my layer extent as a PNG file on ArcGIS. I have already set my data frame extent to the same size as my layer. I want to export this layer image as a PNG, but my page layout is bigger (see image) and when exporting I have these white spaces on my image that I don’t want. I read that I need to pass a DataFrame object to the function’s data_frame parameter, but don’t know how to do it. If anyone knows how can I export a map image to the specific extent of my layer?