boot - How to make an automatic installation ISO image based on ubuntu-18.04-desktop-amd64.iso

I'm working on making the installation of Ubuntu automatic and without any keystrokes in Dell PowerEdge R640.

Attached ubuntu-18.04-desktop-amd64.iso, then rebooted, and the installation started, but in the following process, there are a lot of steps which need manual keystrokes.

For example, the first pop up window:

Try Ubuntu without installing,
Install Ubuntu,
OEM install (for manufactures),
Check disc for defects.

I just want to select the first option and don't want press any key. I guess I should make some changes based on the original ubuntu-18.04-desktop-amd64.iso.

So the key points are:

• How to make such an ISO which support automatically installation?


• Which files need changes?