Hey @wordmeto,
Thank you for reaching out.
Please know that at any time we only support the 2 most recent major versions of WordPress. We don’t recommend running outdated versions of any plugin, theme, or WordPress itself not only for security reasons – but for many more: https://yoast.com/supporting-older-versions-of-wordpress/.
If you need it for testing purposes, please know that you can download older versions of our plugin on the Advanced view: https://www.ads-software.com/plugins/wordpress-seo/advanced/