When you install Sitecore Commerce then it adds a new binding for storefront. You can see the name in your Sitecore Commerce installation file "Deploy-Sitecore-Commerce.ps1". There you can find the hostname provided in "$SiteHostHeaderName" variable.
Can you please double check if you can access your storefront with "http://sxa.sotefront.com" url. Please notice it has http protocol. Please check if "sxa.sotefront.com" binding added with http protocol on your Sitecore site in IIS.
If it still not work then check you have this "InstallPackages.aspx" page in "SiteUtilityPages" folder in your Sitecore site.