Problems moving site to another domain

The simple index.html file works. I tried renaming the .htaccess files but the site still shows a blank page.

Confirm that the server is set up to execute PHP files. Change the name of CodeIgniter's index.php temporarily. Then change the name of the index.html that worked to index.php - does it still now?

Yes. index.php works when it is executing the simple script.

I'm guessing that there is a syntax error in the index.php file that has just been renamed.
Add the following to the new index.php:

PHP Code:

<?php
declare(strict_types=1);
error_reporting(-1);
ini_set('display_errors', '1');
echo __line__; die; 


Call index.php, ensure the line number is displayed correctly then gradually insert the script from the problematic index.php a dozen lines at a time until the blank screen reappears.

I tried that and the blank screen started as soon as i included the first line from original script

define('ENVIRONMENT', isset($_SERVER['CI_ENV']) ? $_SERVER['CI_ENV'] : 'development');

does that mean there is something wrong ith the server? should i contact my server and heck if they are compatible with codeigniter?