Umbrel STEP10 NO external drive found

Support and Troubleshooting
1

I’m trying to connect my Raspberry Pi 4 to umbrel via wifi, and I’m up to step 10, but I’m getting “Error: No external drive found”.
I’ve connected a SanDisk SDSSDH3-1T100 to the blue port and rebooted, but no luck.
What should I do?