Development mode for personal IP address

Hello everyone! Sorry for my bad English, but I try to write my question.
Tell me please, How I can set (or switch on) CI_ENVIRONMENT to DEVELOPMENT mode for my personal IP address?
As example... I have a working web project and I have a bug on any page and I want to switch on development mode, BUT! If I will change .env file and will set development mode this parameter will be set for all clients on my web site. How I can set something:

if($_SERVER['REMOTE_ADDR'] == '12.34.56.78') {
env(' CI_ENVIRONMENT', 'development')
}
I will believe would your understood my question. Thank's!