AntiX-23.1 install - EFI info missing

I installed Antix-23.1 as a second distro. I gave it 50G on sda3 as /. here's the lsblk Code:NAME MAJ:MIN RM SIZE RO TYPE MOUNTPOINTS
sda 8:0 0 931.5G 0 disk
sda1 8:1 0 593G 0 part /mnt/hd/Videos
sda2 8:2 0 1000M 0 part
sda3 8:3 0 50G 0 part
sda4 8:4 0 287.5G 0 part /mnt/hd
sdb 8:16 0 931.5G 0 disk
sdb1 8:17 0 931.5G 0 part /mnt/dvd
nvme0n1 259:0 0 476.9G 0 disk
nvme0n1p1 259:1 0 100M 0 part /boot/efi
nvme0n1p2 259:2 0 16M 0 part
nvme0n1p3 259:3 0 253.5G 0 part
nvme0n1p4 259:4 0 566M 0 part
nvme0n1p5 259:5 0 500M 0 part /boot
nvme0n1p6 259:6 0 60G 0 part /
nvme0n1p7 259:7 0 161.7G 0 part /home
nvme0n1p8 259:8 0 509M 0 partI ran the iso from a usb key, and it had the root passwd. So when it offered to do stuff with grub, and set that up, I said "Yes".

Apart from writing /boot/grub/grub.cfg, it didn't do anything. My EFI partitions are /dev/nvme0n1p1 & /dev/sda2. Now I know the basics, I have to

1. Find some .efi file on the iso.
2. configure EFI to select Antix when it's told to.
3. Configure the boot loader to run the kernel, & initrd.

The probable cause of this is that I didn't assign an EFI partition in setup. What's the Antix way of sorting this mess?