https://www.mywebsite.co.uk/mypage

RewriteEngine On

RewriteBase /

# Force WWW prefix
RewriteCond %{HTTP_HOST} !^$
RewriteCond %{HTTP_HOST} !^www. [NC]
RewriteCond %{HTTPS}s ^on(s)|
RewriteRule ^ http%1://www.%{HTTP_HOST}%{REQUEST_URI} [R=301,L]

# Force SSL
RewriteCond %{HTTPS} off
RewriteRule ^ https://%{HTTP_HOST}%{REQUEST_URI} [R=301,L,NE]

# Remove .php extension
RewriteCond %{THE_REQUEST} ^GET /[^?s]+.php
RewriteRule (.*).php$ /$1/ [L,R=301]

RewriteCond %{REQUEST_FILENAME} !-f
RewriteCond %{REQUEST_FILENAME} !-d
RewriteCond %{REQUEST_URI} ^/(.+)/$
RewriteCond %{DOCUMENT_ROOT}/%1.php -f
RewriteRule ^(.*)/$ $1.php [L]

# Force trailing slash
RewriteCond %{REQUEST_FILENAME}.php -f
RewriteRule .*[^/]$ $0/ [L,R=301]

https://www.mywebsite.co.uk/mypage

https://www.mywebsite.co.uk/mypage/