From Fedora Project Wiki
- Ensure only the single target device you prepared is selected as the installation target disk.
- Click the 'kebab menu' (the three white dots in a vertical line) at the top-right corner, and click "Launch storage editor". Click "Launch storage editor" again to confirm.
- On the Storage screen, delete all existing partitions (if any), using the kebab menu for each partition.
- Create any necessary bootloader partitions (e.g. EFI System Partition for UEFI installs, BIOS Boot partition for BIOS installs onto a GPT disk, PReP boot partition for PowerPC installs).