Balena Etcher, is an Open Source, user friendly and cross platform software used to flash USB disks with disk images in order to make them bootable. You can download it here. For Debian based distributions (like Linux Mint, Ubuntu or Debian), download the .deb file, and the checksum file for Linux: (this is an example for the version v2.1.0, change the filenames accordingly if needed):

wget https://github.com/balena-io/etcher/releases/download/v2.1.0/balena-etcher_2.1.0_amd64.deb
wget https://github.com/balena-io/etcher/releases/download/v2.1.0/SHA256SUMS.Linux.x64.txt

Then you can check that the checksum match. The output of this command:

sha256sum balena-etcher_2.1.0_amd64.deb

should be contained in the output of this one:

cat SHA256SUMS.Linux.x64.txt

Now that you have some level of confidence that you are dealing with a genuine file, you can install it:

sudo apt install ./balena-etcher_2.1.0_amd64.deb

Then launch it:

balena-etcher

(in the two following screenshot it is an example with Tails)