src/Entities/Users/UserProfile.php
public function jsonSerialize()
    {
        return [
            'firstName' => $this->getFirstName(),
            'surname' => $this->getSurname(),
            'email' => $this->getEmail(),
            'nickName' => $this->getNickName(),
            'cellphoneNumber' => $this->getCellphoneNumber(),
            'sex' => $this->getSex(),
        ];
    }
public function jsonSerialize()
    {
        return [
            'firstName' => $this->getFirstName(),
            'surname' => $this->getSurname(),
            'email' => $this->getEmail(),
            'nickName' => $this->getNickName(),
            'cellphoneNumber' => $this->getCellphoneNumber(),
            'sex' => $this->getSex(),
        ];
    }
Specify data which should be serialized to JSON