Autoinstall grub.cfg and txt.cfg

[hamstermandk]

I am trying to create an unattended install but I can't figure out the right syntax for my configs.
I created a custom ISO from ubuntu-20.04-live-server-amd64.iso
I placed "user-data" and "meta-data" in /nocloud

As I can understand I need to both edit grub config and isolinux config.
So I did this, but I can't make it do the unattended install.

/boot/grub/grub.cfg

menuentry "Install Ubuntu Server" {
set gfxpayload=keep
linux /casper/vmlinuz "ds=nocloud;s=/cdrom/nocloud/" quiet autoinstall -
initrd /casper/initrd

/isolinux/txt.cfg

label live
menu label ^Install Ubuntu Server
kernel /casper/vmlinuz
append initrd=/casper/initrd quiet autoinstall ds=nocloud;s=/cdrom/nocloud/ ---

[hamstermandk]

I found that you ONLY need to change the grub.cfg file.
This is working for Ubuntu 20.04 live server

menuentry "Install Ubuntu Server" {
set gfxpayload=keep
linux /casper/vmlinuz quiet autoinstall ds=nocloud\;s=/cdrom/nocloud/ ---
initrd /casper/initrd