Showing the Previous URL after redirecting to another url - apache

Question

I have a retail application that is hosted at www.emenu.com. My clients have there on websites that are hosted on their server, like www.fastfood.com, www.freshlime.com, etc. There is a button on their website which redirects to www.emenu.com.
www.fastfood.com on a button click redirect to www.emenu.com
www.freshlime.com on a button click redirect to www.emenu.com like that,
Problem is that the client does not want to show my application URL in the address bar after redirecting.
ie, www.fastfood.com will redirect to www.emenu.com but it should show www.fastfood.com in URL.
I am using laravel for the development. Came across many solutions involving .htaccess like
Options +FollowSymLinks -MultiViews
RewriteEngine On
RewriteBase /
RewriteCond %{HTTP_HOST} ^(www\.)?emenu\.come$ [NC]
RewriteRule ^ http://www.fastfood.com%{REQUEST_URI} [L,NE,P]
But the solution doesn't work.

Answer 1

The way websites work is like this:
user enters URL into browser (or clicks a link to get there), say www.example.com/foo/bar
the browser/OS looks up the A or AAAA DNS record for www.example.com, this DNS record points to an IP address
the browser sends an HTTP request to that IP address, like:
GET /foo/bar HTTP/1.1
Host: www.example.com
the server at that IP address (hopefully) responds with some HTML
So you see, if the domain www.example.com is already pointed at your client's server, it can't also point at your server. And the URL in the browser's address bar will always show the URL it's currently actually loading, you can't mask that. If you want the contents of your site to appear on your client's domain name, then the server pointed to by the DNS record for that domain actually needs to return the HTML for your site. You pretty much have two options there:
Embed your site in an iframe on your client's page. Say www.example.com/emenu.html contains:
<iframe src="http://www.emenu.com"></iframe>
Then visitors going to www.example.com/emenu.html will see the content of your site (embedded into a site of your client).
Set up the web server for www.example.com to reverse-proxy (some of) your URLs. In Apache that can be done with something like:
ProxyPass "/emenu" "http://www.emenu.com/"
ProxyPassReverse "/emenu" "http://www.emenu.com/"
Any HTTP request for the URL path /emenu to www.example.com would be forwarded by that server to your server, and the response be presented to the visitor as if the www.example.com server had produced it itself.