@vanMacG : Yes it was a typo, the ’fastboot flashing unlock’ command run well 
@rik I’m don’t think sudo is required, as first commands using fastboot worked…
I’ve found a post with another person having trouble installing iodéOS on a lemonadep : Initial state before installing iodé and fastboot issues - #13 by slomo
I tried to put my phone in fastboot mode and type each command of flash-all.sh script one after another, and the problem comes when doing :
fastboot --skip-reboot update iode-7.5-20260506-lemonadep-img.zip
Although the –skip-reboot option was set, the phone reboots during the process :
extracting super_empty.img (0 MB) to RAM…
extracting vbmeta_system.img (0 MB) to disk… took 0.000s
archive does not contain ‘vbmeta_system.sig’
extracting super_empty.img (0 MB) to RAM…
Sending ‘vbmeta_system’ (4 KB) OKAY [ 0.002s]
Writing ‘vbmeta_system’ OKAY [ 0.001s]
extracting super_empty.img (0 MB) to RAM…
extracting vbmeta_vendor.img (0 MB) to disk… took 0.000s
archive does not contain ‘vbmeta_vendor.sig’
extracting super_empty.img (0 MB) to RAM…
Sending ‘vbmeta_vendor’ (4 KB) OKAY [ 0.002s]
Writing ‘vbmeta_vendor’ OKAY [ 0.001s]
Rebooting into fastboot OKAY [ 0.002s]
< waiting for any device >
And the phone restart on another menu (that I don’t recognize) :
and I don’t know what to do next …
I don’t understand why fastboot says “Rebooting into fastboot” whereas the –skip-reboot option was given ?!?