CodeIgniter 4.6.0 Deploy Issue

I deployed CodeIgniter 4.6.0, but I'm encountering a syntax error in the Config/App.php file related to the public string $baseURL declaration. When I remove the string type declaration, the error shifts to the next line. Additionally, other configuration files, such as Routes.php, are also showing similar string or array syntax errors. Can someone help me properly install and configure CodeIgniter 4.6.0?