Click on the "Run script" button on the upper right of the screen, close to the search bar
Go to export_scripts → "Batch Image Export ..."
Enter additional parameters for the export, don't forget to choose the format of the images
Click on Run Script to confirm and generate a zip file.
When the zip file is ready, it will be shown in the Activities Menu (between the "Run script" button and the search bar)
Click on the download file icon Currently, long file names are an issue and may hide the download file icon. To circumvent the issue, select first a dataset or a file with a short name (you can edit the name of a file temporarily to do that, but don't forget to rename it afterward).