require

Remember, when using require that it is a statement, not a function. It's not necessary to write:
<?php
 require('somefile.php');
?>

The following:
<?php
require 'somefile.php';
?>

Is preferred, it will prevent your peers from giving you a hard time and a trivial conversation about what require really is.

If your included file returns a value, you can get it as a result from require(), i.e.

foo.php:
<?php
return "foo";
?>

$bar = require("foo.php");
echo $bar; // equals to "foo"

Always use __DIR__ to define path relative to your current __FILE__. 
(Or another setting that is originally based on __DIR__/__FILE__)

try & catch - don't get confused by the words "fatal E_COMPILE_ERROR" - it's still just an internal Error that implements Throwable - it can be caught:

<?php
try {
    require(__DIR__ . '/something_that_does_not_exist');
} catch (\Throwable $e) {
    echo "This was caught: " . $e->getMessage();
}
echo " End of script.";
?>

Note that this will still emit a warning "Failed to open stream: No such file or directory..." ...unless you prefix the require with "@" - which I strongly don't recommend as it would ignore/supress any diagnostic error (unless you have specified set_error_handler()). But even if you'd prefix the require with "@" it would still be caught.