Let's Encrypt won't follow redirect to URL with port 10000

Virtualmin
26

So you’re saying that if the domain is example.com, I have to change this directive at Virtualmin -> EXAMPLE.COM -> Services -> Configure Website -> Edit Directives (and Virtualmin -> EXAMPLE.COM -> Services -> Configure SSL Website -> Edit Directives) from this:

RewriteCond %{HTTP_HOST} =admin.example.com
RewriteRule ^(.*) https://admin.example.com:10000/ [R]

… to this:

RewriteCond %{HTTP_HOST} =admin.example.com
RewriteRule ^(.*) https://example.com:10000/ [R]

Is that right? And I must leave the port number in?

Or should I just take them out?