After Disk Utility loads select the drive (out-dented entry with the mfg.'s ID and size) from the side list.Open Disk Utility in the Utilities' folder.You will need a 16GB USB flash drive that has been partitioned and formatted for use with OS X as well as an installer for Catalina. Simply use the Terminal command by copying and pasting the command line into the Terminal window. Second, read this How To outline for creating a bootable macOS installer. First, review this introductory article: Create a bootable installer for macOS.
