Trouble installing macOS Ventura on external SSD

I followed the steps in the link you sent me. It all seemed to go well, but after the last re-start the internal HD

re-started the computer.

I went to system settings, picked the start-up disk, picked the SSD, restarted, and got this message.

In case this helps someone else, I was finally able to install and run Ventura on the external SSD. I read that someone was able to accomplish, after having all the issues I was having, by using a USB connection into the computer with the USB-C end connected to the SSD. Worked on the first go around. After a day or so, I shut down the computer and installed the original USB-C cable with no problem.

Hope that made sense.

The SSD was connected with the USB-C cable that came with the LaCie SSD. Make no sense to me either. But after trying to install numerous different ways, I figured I had nothing to lose. I'm just happy it worked.

Thanks. It works okay. Sometimes, it's a bit slow, it dosen't like Safari, so I use Firefox which runs fine.

I will try the Carbon Copy Cloner.

No, they were all uninstalled after the last question I asked regarding a file problem. That conversation led to my purchasing an external SSD.