It's super easy - you don't need to go through composer or anything like that (although if you maintain a website and need a lot of patches to keep it working, it's useful to learn how to use composer in the long run).
Here's how you do it:
Go to the directory where the 'radix' module is installed. Relative to web root, this should be something like /modules/radix
or /modules/contrib/radix
. Download the patch into that directory - for example, you can use wget https://www.drupal.org/files/issues/2022-01-11/3173811.patch
or you can use ftp or any other method you like.
Then, in the same directory where you download the patch, use the command patch -p1 < 3173811.patch
.
This assumes you are using a variety of Unix for your website - these commands are available on most distributions. If you are on Windows, you can also find these exact commands but you might have to install the commands yourself.
If that is still too big a barrier, for this patch at least, fixing the code manually is always an option. The patch just corrects two "use" statements:
-use Robo\Task\Archive\loadTasks as ArchiveTaskLoader;
-use Robo\Task\Filesystem\loadTasks as FilesystemTaskLoader;
+use Robo\Task\Archive\Tasks as ArchiveTaskLoader;
+use Robo\Task\Filesystem\Tasks as FilesystemTaskLoader;
The patch is saying that the first two lines need to be deleted (that's what the minus sign means) and the second two lines need to be added in the same place (that's what the plus sign means). The format of the patch uses the first column to show you what to change - if there is nothing in the first column, the line doesn't get changed. If there is a - in the first column, the line gets deleted. If there is a + in the first column, the line gets added. That first column is only used in the patch, it should not appear in the code either before or after you change it.