This example will add a new keyword to a blacklist to classify it as spam

add_filter( 'frm_filename_spam_keywords', 'my_custom_function' );
function my_custom_function( $spam_keywords ) {
    array_push( $spam_keywords, 'another' );
    return $spam_keywords;
}

Replace the keyword 'another' with the one you need to add

This example will remove one of the default keywords classified as spam

add_filter( 'frm_filename_spam_keywords', 'my_custom_function' );
function my_custom_function( $spam_keywords ) {
    $key = array_search( 'robux', $spam_keywords ); // Replace the keyword 'robux' with the one you need to remove
	if ( false !== $key ) {
		unset( $spam_keywords[ $key ] );
	}
    return $spam_keywords;
}

Currently these are the default keywords fortnite, vbucks, roblox, robux

This example will disable the spam validation for this hook

add_filter( 'frm_filename_spam_keywords', '__return_false' );