Booting from SSD

Reasonably competant with Mac or Windows but complete beginner Pi.
Have new Pi4 and KingDian SSD
Have tried a number of times to install 2 OS’s Buster and Majaro to boot from SSD using BerryBoot mostly following the YouTube video from ETA Prime. Failed with external OS’s so went for simple single OS on the SSD but failed everytime with something like this message

Could anyone give me some idea what I am doing wrong?
The installation to the SD card goes without a hitch.
Thanks in advance.

I do believe, to do that without an SD card, you need to flash the beta firmware to your Pi 4B.

Thanks alphanumeric.
Just to be clear, I am not trying to “do that without an SD card”, but to use the SD card to boot whilst having the OS or multiple OS’s on the SSD.
If the solution is as the link you provided then I fear it is beyond my capabilities.
However this discussion is quite recent and YouTube videos on the topic from ETA PRIME, Leepsvideo and others make no mention of this requirement and seem to predate it.
Having looked at these again, I wonder if it makes any difference which port is used for the SSD because one contributor makes specific reference to plugging in to the bottom right.

Ok, I wasn’t sure which way you were trying to do it.
The boot from SD card, run the OS from the SSD has been around for a while.
And I believe there was a bit that could be set in the Pi 3B to enable booting right from USB.
They have been screaming for this option on the Pi 4 on the Pi forums for a while now.

I found this after hunting around, just scroll down to the USB Boot instructions bit.

Thanks again alphanumeric.
That looks reasonably straightforward and I will have a go over the weekend, but I think I will first see what happens with the SSD plugged into the USB2 port, out of interest.
Learning all the time even at my advanced years!

Ditto to the , learning all the time, and advanced years, lol. =)

OK Novice user trying to follow the procedure set out by James A Chambers in link above.
Almost last step is to “Change PARTUUID” and suggestion is d34db33f.
How do I enter that? Do I copy and paste the whole of that script? Or do I modify it in some way with this hexadecimal
Disc Identifier in that script seems to have been changed from 0x6c586e13 to 0xd34db33f so is that not the same as d34db33f?
Again sorry for my ignorance, but would do much better talking about producing stainless steel!

Note: If I enter:
sudo fdisk /dev/sda
I get:
Welcome to fdisk (util-linux 2.33.1).
Changes will remain in memory only, until you decide to write them.
Be careful before using the write command.
Command (m for help):

Does that help?

I’ve never done anything like that before. As near as I can tell, the bits you type in and when are in bold type
sudo fdisk /dev/sda
then type p
then x
then i
now type in the 0xd34db33f and hit enter, the next message should be the
Disk identifier changed from xxxxxx to 0xd34db33f
then type r
and w to save it.