Get this PrestaShop module from the official PrestaShop marketplace: https://addons.prestashop.com/en/seo-natural-search-engine-optimization/27235-webmaster-site-verification.html

Website Verification Prestashop Module is a module that can help you add any site verification code and any custom script in the head of your website, very fast and easy without the requirement of any coding skills.

Features:
Easy installation.
Nicely integration.
Search Engine Optimization (SEO).
Including Google, Yahoo, Bing, Alexa, Yandex, Mywot, Norton Safeweb, Pinterest.
Verification is possible using the “HTML Meta-Tag” method.
Adds each HTML Meta-Tag in the head section of your website dynamically.
Adding your sitemap file into the Sitemap files section.
See a complete statistics on your site’s activities within search engine.
Seo Friendly, indexing your site and of all necessary SEO for you without your Store.
Allow Bots to crawl your site on daily basis.
SEO Reports, Necessary SEO and SEO Analyzer.
Support Multistore.
Full documentation.
Full Support.