Fix check Register AddBirthdayValidation.php

[Litalino]

public function __invoke(UserValidator $flarumValidator, Validator $validator): void
    {
        $rules = $validator->getRules();

        $isRequired = $this->settings->get('datlechin-birthdays.required')
            && $this->settings->get('datlechin-birthdays.set_on_registration');

        if ($isRequired  && ! $flarumValidator->getUser()) {
            $set_isRequired = 'required';
        } else {
            $set_isRequired = 'nullable';
        }

        $rules['birthday'] = [
            //'nullable',
            //Rule::requiredIf($isRequired && ! $flarumValidator->getUser()),
            $set_isRequired,
            'date_format:Y-m-d',
            'before:today',
            function ($attribute, $value, $fail) {
                if ($value) {
                    $birthday = new DateTime($value);
                    $now = new DateTime();
                    $diff = $now->diff($birthday);
                    if ($diff->y <= (int) $this->settings->get('datlechin-birthdays.min_age')) {
                        $fail($this->translator->trans('datlechin-birthdays.api.invalid_age_message', [
                            'minAge' => (int) $this->settings->get('datlechin-birthdays.min_age')
                        ]));
                    } else if ($diff->y > 100) {
                        $fail($this->translator->trans('datlechin-birthdays.api.invalid_dob_message'));
                    }
                }
            },
        ];

        $validator->setRules($rules);
    }

[datlechin]

Fixed!