incomprehensible commands
The script uses several commands that I can't interpret: flatstring, hexbin, base64url.
I can't install them on my server Ubuntu 20.
apt install flatstring hexbin base64url
Reading package lists... Done
Building dependency tree
Reading state information... Done
E: Unable to locate package flatstring
E: Unable to locate package hexbin
E: Unable to locate package base64url
what are these programs and where can I get them?