Please follow the below mentioned steps in order to verify the domain at Google webmaster tools.
Go to Webmaster Tools verification page and confirm the successful uploading of the HTML file.
Then simply click on the Verify button to finish the process.
The next step is to submit your website’s sitemap to Webmaster Tools.
To start, navigate to Crawl > the Sitemaps menu.
Then simply click on the Add/Test Sitemap button.
In the pop-up window, indicate the name of your sitemap file and click on Submit Sitemap to finish.