TypeError: argument not optional

Hi good people, learning to code on codecamp, am doing the Nest an Anchor within a paragraph but am getting "TypeError: argument not optional " and I cannot get past that. What does it mean and how can I go about it, please help

Can you please show us the code you have written?

When you enter a code block into a forum post, please precede it with a separate line of three backticks and follow it with a separate line of three backticks to make easier to read.

See this post to find the backtick on your keyboard. The “preformatted text” tool in the editor (</>) will also add backticks around text.

Note: Backticks are not single quotes.

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