In this article, you will learn how to Remove the Website URL field from WordPress comments.
You need to navigate to your WordPress Appearance -> Editor and select the functions.php file from the right menu. You need to paste this code under the <?php line.

add_filter('comment_form_default_fields', 'unset_url_field');
function unset_url_field($fields){
if(isset($fields['url']))
unset($fields['url']);
return $fields;
}
Don’t forget to Update the file.
Now you have Removed the Website URL field from your WordPress page comments.
Before you Removed the Website URL field from your WordPress page

After you Remove the Website URL field from your WordPress page.

Once your website is growing and you will get popular the DA (Domain Authority) will increase and everyone will want to reserve a backlink on your website, so they take advantage of placing a simple comment on your blog with their website.
What is DA – Domain Authority?
Domain authority (also known as site authority and website authority) is a metric used by SEOs to estimate how “rankable” a website is as a whole.
You may also want to STOP the spam comments on your WordPress website
Spam comments are a significant issue for all blogs. But Google released reCAPTCHA that enables web hosts to distinguish between human and automated access to websites. The original version asked users to decipher hard to read text or match images.
Installing WordPress reCAPTCHA:
Step 1 – Log into your WordPress Dashboard
Step 2 – Navigate to Plugins, then click Add New.

Step 3 – In the search box type wp-recaptcha and hit enter. Click Install Now next to the WP-reCAPTCHA plugin.

Step 4 – Activate the Plugin link, and the WP-reCAPTCHA plugin will be installed and enabled.

You may need to check the how Setup of reCAPTCHA API Keys.