Now you need to create a Backup of the SD Card. You can use whatever software you like.

In the Screenshot, I'm using the built-in disk management of Linux Mint.

On Windows, you can use Programs like Win32DiskImager.

On macOS, you can use Disk Utility. Select the SD Card volume, click File > New Image > Image from "[SD Card volume name]"

On Windows & macOS, you will also get a bunch of messages urging you to format the partitions. Do not format any of them. It will irrecoverably brick your device!

It's not enough to copy-paste the files from the partitions that have been recognized in your Operating system. You have to use a tool to create an image of the entire card.