Here is how you can create a bootable USB installer on macOS. To make a bootable USB for Mac, first download the OS version you want by simply searching for it online. You will find an official App Store link from Apple, where you can download it directly. However, if you want the latest macOS version, which is Tahoe at the moment, you will need to use Terminal to download it.

To download Tahoe, run the following command:
softwareupdate –fetch-full-installer –full-installer-version 26.3

This will download version 26.3. Please note that you will only be able to download this version if your macOS is eligible. The file size is approximately 17 GB.

After the download completes, go to your Applications folder. There, you will see Install macOS Tahoe. Also note that if you previously downloaded an earlier version, the newly downloaded version may replace it, so be sure to keep a proper backup. You can also copy the Tahoe installer to a USB drive or another storage device for backup.

Now, to create a portable USB installer:

Insert a pen drive and make sure you have backed up all files from it, as the drive will be formatted. Next, visit the official website of Apple. There, you will find all the details about the installer and how to create it. Depending on the OS version you downloaded, whether Tahoe or another version, copy the respective commands. One important detail is the USB drive name, which must exactly match your pen drive’s name. You can either modify the command or rename your USB drive to MyVolume.

After that, copy the appropriate command from the website, open Terminal, paste the command, and press Enter. Enter your macOS login password when prompted. The system will warn you that all files will be erased. Type Y and press Enter.

This entire process may take about 20–30 minutes, so please be patient. Once completed, you can use your pen drive as a bootable macOS installer.

Thank you very much.