In step 3 when I Open file InstallMacOSX.pkg it says This version of OS X 10.11 cannot be installed on this computer.

I am running these steps on macOS Catalina on my MacBook

I tested the steps using a High Sierra in VirtualBox. The host is a 2013 iMac running Catalina. Let me know if the answer works with Catalina so I can update the answer.

In step 3 when I open file InstallMacOSX.pkg it says “This version of OS X 10.11 cannot be installed on this computer”

What is the model/year of the Mac running Catalina? You may not be able to install if the Mac can not actually run El Capitan.

MacBook Pro 2017 with touchbar

The original operating system on that model was macOS 10.12.5

I think there is a confusion here. I have two machines 1 iMac 2009 24” and one MacBook Pro 2017 touchbar. The iMac I cannot open at all as I erased everything from the Macintosh HD and I am trying to fix so I am trying to follow your steps on my MacBook Pro so I can create this bootable USB for the iMac to boot the iMac from. So when I follow these steps on the MacBook Pro I get stuck in step 3 as it says “This version of OS X 10.11 cannot be installed on this computer” so I don’t know what shall I do?

And advice?

I am testing a procedure for creating the USB flash drive installer on your 2017 Mac.

Okay, thank you, please let me know and tag or mention me so I can get notified :)

I appreciate your help