How to rewrite url created in slim framework?

I have to rewrite url. I am using slim framework v3 to create api. My current url is like this,

current url = http://ift.tt/2qwUiw3

But i want remove api.php extention so need url like this

http://ift.tt/2m6TEAE

I know we have to rewrite url in .htaccess file, i tried same. my .htacees file is like this

##Workign on normal server
RewriteEngine on`
RewriteCond %{HTTPS} =off
RewriteCond %{HTTP_POST} !^www.myapp.com [NC]
RewriteRule ^(.*)$ http://ift.tt/2qAJ1L4 [L,R=301]

I tried solution from slim documentation but not working.. please help me.. thank u..