Return type of OCA\TwoFactorGateway\Provider\State::jsonSerialize() error

[oleua]

Hi! I am getting error in nextcloud journal

Return type of OCA\TwoFactorGateway\Provider\State::jsonSerialize() should either be compatible with JsonSerializable::jsonSerialize(): mixed, or the #[\ReturnTypeWillChange] attribute should be used to temporarily suppress the notice at /var/www/html/nextcloud/apps/twofactor_gateway/lib/Provider/State.php#125

referencing to

public function jsonSerialize() {
                return [
                        'gatewayName' => $this->gatewayName,
                        'state' => $this->state,
                        'phoneNumber' => $this->identifier,
                ];
        }