PHP: Accessing variables created with add_action() - php

Question

I'm kinda learning php as I go along here (though I do have some experience in other languages), so I'm hoping someone can point me in the right direction.
I'm using an add_action() function in functions.php to access the form data from an Elementor form. Works fine from within add_action(), however I cannot return any of the variables to make them available elsewhere within functions.php (I've tried adding "return $fields").
There's probably an easy solution, but I've been wracking my brain all weekend, and haven't gotten anywhere. Any thoughts?
Side Note: I've read elsewhere that using filters may be a solution, but it doesn't seem to be as simple as changing "add_action()" to "add_filter()".
add_action( 'elementor_pro/forms/new_record', function( $record ) {
$form_name = $record->get_form_settings( 'form_name' );
if ( 'MyElementorForm' !== $form_name ) {
return;
}
$raw_fields = $record->get( 'fields' );
$fields = [];
foreach ( $raw_fields as $id => $field ) {
$fields[ $id ] = $field['value'];
}
$letter_type = $fields['LetterType'];
// Send Test Email //
if($letter_type === "1"){
$message = "Upload";
} elseif($letter_type === "0"){
$message = "PDF";
} else {
$message = "Fail " . gettype($letter_type) . " " . $letter_type;
}
mail(
"my#email_address.com",
"Test",
"Test Message " . $message
);}, 10, 2);