Please share code instead of screenshots. 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.
Looks like you added it to the wrong part. It needs to be put up top in the <style> section.
Put <table class="sr-only"> back where it was. Delete everything you added after it. See up at the top where it says <style> and then below it it says .sr-only { …the attributes are already listed below that with blank spaces where you can fill in the values.