Do I have to upgrade to edit a site built on 1.3 version of cakephp

I have been given the job to work on a site that was built on 1.3 v cakephp. We don’t have the development server or anything other than the production code. I am VERY new to CakePHP, but not PHP. What is recommended in this circumstance? Thank you!

Cake 1.3 now is more than 5 years old. If you want to do some small changes, just go ahead, it will work - except if you are using PHP 7.

For bigger changes the best way would be rewrite the whole thing for CakePHP 3.

I would not reccomend to update it. Resons are here: Upgrading from 1.2