htaccess remove .php but allow post requrest code example

Example 1: php remove extension from url

//put this piece of code in the root file .htaccess
RewriteEngine on
#remove extension html
RewriteCond %{REQUEST_FILENAME} !-d
RewriteCond %{REQUEST_FILENAME}\.html -f
RewriteRule ^(.*)$ $1.html [NC,L]

#remove extension php
RewriteCond %{REQUEST_FILENAME} !-d 
RewriteCond %{REQUEST_FILENAME}\.php -f 
RewriteRule ^(.*)$ $1.php

Example 2: remove .php from url

# Apache Rewrite Rules
 <IfModule mod_rewrite.c>
  Options +FollowSymLinks
  RewriteEngine On
  RewriteBase /

# Add trailing slash to url
  RewriteCond %{REQUEST_FILENAME} !-f
  RewriteCond %{REQUEST_URI} !(\.[a-zA-Z0-9]{1,5}|/|#(.*))$
  RewriteRule ^(.*)$ $1/ [R=301,L]

# Remove .php-extension from url
  RewriteCond %{REQUEST_FILENAME} !-d
  RewriteCond %{REQUEST_FILENAME}\.php -f
  RewriteRule ^([^\.]+)/$ $1.php 

# End of Apache Rewrite Rules
 </IfModule>