Use the Android device to complete the production of the computer boot disk installation disk through otg, and write the iso image on the U disk through the mobile phone

Take my Ubuntu system as an example.

First install the Etchdroid Android App or Baidu search name to download and install, open the App like this.

Then go to the Ubuntu official website download address to download the required version image file.

Then connect the U disk to the mobile phone through the OTG converter, open Etchdroid, select the first item, then select the downloaded image file, and then select the corresponding U disk. Then you can see the writing progress in the notification bar.
Wait for progress to 100%

Then you can use the U disk to start the computer to install the system.