QGIS-SaveLayouts.py

# Run in QGIS
# Save all the layouts as PNG files from the current project.
outurl = '/Users/USERNAME/' # using ~ does not work?
outformat = '.png'
outdpi = 200
manager = QgsProject.instance().layoutManager()
for layout in manager.printLayouts():
    print('Saving: ' + layout.name())
    
    layout = manager.layoutByName(layout.name())
    exporter = QgsLayoutExporter(layout)

    legendExporter=QgsLayoutExporter(layout)
    imageSettings=legendExporter.ImageExportSettings()
    imageSettings.cropToContents=True
    imageSettings.dpi=outdpi

    legendExporter.exportToImage(outurl + layout.name() + outformat,imageSettings)