It works in Fedora 33 now. See Rapid Photo Downloader: Download and Install for download. On that page there is a link to install.py (https://launchpad.net/rapid/pyqt/0.9.26/+download/install.py) file. Download and execute with “python3 install.py” on Fedora33.
Start the program with “rapid-photo-downloader” in terminal, or find the icon in GNOME menu.