If you cannot verify the uploaded file from google you have to use DNN Page Header Tag section by going to the site's Home page. From the Common Tasks choose Edit. Scrool down until you see Advanced Settings and there you will find Page Header Tag. Copy and paste the meta tag link from google and you can verify the ownership of your DotNetNuke website.

Your meta tag from google should look something like this:  <meta name=“google-site-verification” content=“32456345b6m345b3j45lk34g5lk34h5lk6345k6” />

If you wanna see a clip about this check this video from DNNHero.com: Pt8x45A4XXU