Htaccess mod rewrite don't work - apache

Question

I have a project with two applications: a frontend (in AngularJs) and a backend (in Phalcon). I my server document root i have two folders and one htaccess:
public_html
- api
- controllers
- index.php
- app
- .htaccess
The .htaccess have the next configuration:
<IfModule mod_rewrite.c>
RewriteEngine on
RewriteCond %{REQUEST_FILENAME} !-f
RewriteRule ^api/(.*)$ api/index.php?_url=/$1 [QSA,L]
</IfModule>
RewriteCond %{HTTP:Authorization} ^(.*)
RewriteRule .* - [e=HTTP_AUTHORIZATION:%1]
So, when i send a POST request (for example) to http://mydomain/api/sessions, the result is 404 not found. The router configuration is:
$router->addPost('/sessions', array(
'controller' => 'sessions',
'action' => 'post'
));
In my localhost works fine with this configuration. But, in my VPS not.
Any ideas ?
Update 1:
If i don't use any REST service, accessing via http://mydomain/api the Phalcon index controller is loaded.
Update 2:
If i try to access a REST service using a Phalcon url like http://mydomain/api/index.php?_url=/licenses works fine.

Answer 1

i found the problem. the virtual host configuration file had not the next lines:
<Directory "/var/www/domain/public_html">
Options All
AllowOverride All
Allow from all
</Directory>

Answer 2

You can sometimes get away with relative path substitutions in the document root, however, you should make the RewriteRule substitution root-relative (starts with a slash), or specify a RewriteBase / directive after you enable the rewrite engine in order to explicitly specify the URL prefix.
RewriteRule ^api/(.*)$ api/index.php?_url=/$1 [QSA,L]
Becomes:
RewriteRule ^api/(.*)$ /api/index.php?_url=/$1 [QSA,L]