On Ubuntu, if you want to create a Bootale USB to boot to install the Operating System, Hirent Boot USB to save data, please refer to the in...

On Ubuntu, if you want to create a Bootale USB to boot to install the Operating System, Hirent Boot USB to save data, please refer to the instructions below.
To create the Bootable USB, we use the Startup Disk Creator software. This is the software that comes pre-installed on HDH Ubuntu, so you can always use it without having to install. If you are using another Linux or for some reason not pre-installed, please refer to the installation instructions below.
Install Startup Disk Creator
Install with the following command:
sudo apt install usb-creator-gtk
Create a Bootable USB using Startup Disk Creator
Open the Startup Disk Creator software, we have the software interface as shown below.
Click [Other] to load the .iso file => Click [Make Startup Disk]

In case your USB is containing data it will display the following warning:
Click [Yes] if you agree to write up the data in the USB, or [No] to keep stop.

It will write the .iso file to the USB

After recording is complete, it will announce the end. Click [Quit]

So you have successfully created 1 Bootable USB already.
Mr. Nerd