problème installation en mode BIOS Ubuntu 20 (Unable To fond a medium. ..)

[geole]

Hello

After having copied the file / ventoy / ventoy_os_param on another usb key to access it from a system installed on my machine, it was impossible for me to read the content.
I have this in the properties of the file:
type: modèle (binaire) STL 3D (model/x.stl-binary)
taille: 2.3 ko (2,324 octets)

no applications on my machine that can read this type of file.
Addition: Would it be an STL file (3D printing)?
Here is what it gives by forcing the opening with Gedit:

www.ventoy.netaXXXXXXXXXXXXXXXX\00þÀ\00\00\00\00\00\00/ubuntu-20.04.1-desktop-amd64.iso\00\00\00\00\00\00\00\00\00\00\00\00\00\00\00\00\00\00\00\00\00\00\00\00\00\00\00\00\00\00\00\00\00\00\00\00\00\00\00\00\00\00\00\00\00\00\00\00\00\00\00\00\00\00\00\00\00\00\00\00\00\00\00\00\00\00\00\00\00\00\00\00
....