Field is required CSV Importer

public static function getColumns(): array
    {
        return [
            ImportColumn::make('first_name')
                ->requiredMapping()
                ->label('Voornaam')
                ->guess(['voornaam', 'voornaam.'])
                ->example('John')
                ->rules(['required', 'max:255']),
            ImportColumn::make('last_name')
                ->label('Achternaam')
                ->guess(['achternaam', 'naam', 'familienaam', 'achternaam.', 'naam.', 'familienaam.'])
                ->example('Doe')
                ->rules(['max:255']),
            ImportColumn::make('email')
                ->label('Email')
                ->guess(['mail', 'e-mail', 'mail.', 'e-mail.', 'email.'])
                ->example('[email protected]')
                ->rules(['email', 'max:255']),
            ImportColumn::make('phone')
                ->label('Telefoonnummer')
                ->guess(['gsm', 'telefoon', 'gsmnummer'])
                ->example('+32 470 52 60 33')
                ->rules(['max:255']),
            ImportColumn::make('role')
                ->label('Rol')
                ->guess(['rol', 'role.', 'rol.'])
                ->example('Zaakvoerder')
                ->rules(['max:255']),
            ImportColumn::make('notes')
                ->label('Notities')
                ->guess(['notities', 'opmerkingen', 'opmerking', 'opmerkingen.', 'opmerking.', 'note', 'notitie'])
                ->example('Bouwflow is fantastisch!'),
        ];
    }