Curl: no URL Specified (Even though there is a URL)

As seen in the image I am using the curl command appropriately with URL but still there is an error. What is the issue?

I am following this tutorial:

2 Answers

You have substituted -o (lower case) in place of -O (upper case), causing the URL to be interpreted as the name of an output file. From man curl:

 -o, --output <file> Write output to <file> instead of stdout.

versus

 -O, --remote-name Write output to a local file named like the remote file we get.

The -o (small alphabet o) is used to output to a file. When you use this option curl uses the next argument as the name of file and expects another argument for the URL.

The tutorial that you have mentioned uses the -O (capital alphabet O) option. You can learn more about these by running

curl --help