[font=Arial,]We are using yii2 basic application template. We have a domain registered with Google and a hosting service of Linux VPS server with Host Gator.[/font]
[font=Arial,]We want our application to be used internally not to be accessible by all on the internet i.e, our application should be accessible by only our organization’s employees or within a certain range of kilometers. Others should not be able to access it at all.[/font]
You should be able to whitelist the IP for that. Only whitelist IP on your server for those who you want give the server access. I have done this on my server. I have hosted my app on a Linode server using a managed PHP and MySQL Hosting provider. I have to whitelist IPs of my freelance developers and for remote mysql connection though.