Better yet, install Yoast SEO plugin and an XML site map is automatically created for you. You can then submit that sitemap to Google Console.
Managed WordPress hosting does not offer cPanel. You would need cPanel hosting to have a cPanel.
The best way to upload sitemap is by using yoast seo plugin. you have just paste the sitemap URL in your search console and when you add any new pages, post or images, it automatcally add to the sitemap file.
Easiest way to add a Robots.txt to the Managed Wordpress Hosting account is to do as follows:
1) Go to Managed Wordpress Hosting.
2) Select the site.
3) On the upper right hand corner you will find three (...) dots. Select these dots and a drop down will appear from the Managed Wordpress Hosting. Another way is to simply select the WP Admin.
4) In the right hand corner you will find the SFTP (ON). You will also find the hostname and temporary password.
You may change this information. Using FileZilla, simply place the host name as the site you are uploading to sftp://12345. The user name. And the password.
Once uploaded. Go to Google Search Console and run a test of the Robots.txt file you uploaded. If it doesn't appear at the time do a Google Search Crawl of the site: 12345/robots.txt file. Then re-test your settings. You will receive a response with the specifics of the crawl from Google with the details of your Robots. txt file. From here, you should be good to go.