When setting product keyword meta tags, sitewide tags are added?

I have manually set the Meta Tags for products but the sitewide tags are being added on the end, which I do not want for my SEO. How can I stop this pls?

it is in includes>templates>yourtemplate>common>html_header.php

remove the red text and add your own.

Caution. all of your pages will have the same meta tags.

Hello usernameone,
changing html_header.php is not fixing the problem correctly. On my products page, I have meta tag keywords=(keyword1, keyword2, keyword3,..<followed by keywords from <?php echo META_TAG_KEYWORDS; ?>. I want to keep the keyword1 through keyword3, but remove the additional keywords defined with the php code.

If I remove it from html_header.php it is going to remove the keywords for the main index page which is not a good idea.

How can I remove those keywords from the product display page only and keep those keywords in the main index page?

Thanks.