I need a little guidance.

I'm working with the Linux Live Kit to make a redistributable distro I'm working on.
Linux Live Kit found here: https://www.linux-live.org/
I use_linux_iso.sh to create linux-x86_64.iso and it does that just fine, but where I need guidance is the USB portion.

I use these commands to setup the USB after I have the linux-x86_64.iso file created.

plug in usb thumb drive
fdisk -l
to see where usb is located
to burn iso to usb drive
dd bs=4M if=linux-x86_64.iso of=/dev/sdb

This copies files over to the USB but it does not make it bootable.
What do I need to do to make this a bootable usb? I must be missing something.

Any help would be appreciated.

To make your ISO bootable from a USB drive you need isohybrid.

https://www.syslinux.org/wiki/index.php?title=Isohybrid

Ok, I’ll look into that, thank you.

If using live kit there is no need to dd the iso to usb, simply copy mounted iso's content to fat32 usb and as root issue command "syslinux -s /dev/sdx" where /dev/sdx is your usb, may be /dev/sdc1, etc.
You can use Unetbootin also.
Plus if you dd it I dont think persistence will work either.
Also, what distro are you using it on? Debian? Slackware?

I’m using Debian.

Whic version of Debian? Also, did it work for you using unetbootin or manually copying to usb?

did you do this from the website you linked?