"Hints
All versions of Clonezilla live support machine with legacy BIOS. If your machine comes with
uEFI secure boot enabled, you have to use AMD64 (X86-64) version (either Debian-based or Ubuntu-based) of Clonezilla live.
Checksum files are GPG signed by DRBL project, which has the fingerprint: 54C0 821A 4871 5DAF D61B FCAF 6678 57D0 4559 9AFD. To verify, you can follow this doc.
Once you have the Clonezilla live iso or zip file, please follow this Live CD/USB doc to put it on the boot media, and follow this Live Docs to use it.
"
https://clonezilla.org/downloads.php
Did you follow the hints?