How to deserialize JSON to enum in Java?

Question

I am creating an API to simulate a vending machine and I'm using Spring, JPA and MySQL. I have an endpoint for a POST request that allows for new user creation by entering the user's details into a table called users however, I am having trouble deserializing the JSON from the request to an enum. None of the solutions I have found online have worked including all of the deserialization solutions involving annotations that can be found here https://www.baeldung.com/jackson-serialize-enums.

This is the exception message I get when making a POST request using Postman:

2023-01-21T02:50:05.712Z  WARN 9544 --- [nio-8080-exec-1] .w.s.m.s.DefaultHandlerExceptionResolver : Resolved [org.springframework.http.converter.HttpMessageNotReadableException: JSON parse error: No enum constant com.vendingmachine.springboot.utils.Role.buyer]

When I have the role as BUYER in the POST request, it works fine but I want it to be case insensitive.

User class:

@Entity
@Table(name = "users")
public class User
{
    @Id
    @GeneratedValue(strategy = GenerationType.IDENTITY)
    @Column(name = "id")
    private int userId;

    @NotNull
    @Column(name = "username", unique = true)
    private String username;

    @NotNull
    @Column(name = "password")
    private String password;

    @NotNull
    @Column(name = "role")
    private Role role;

    @NotNull
    @Column(name = "deposit")
    private BigDecimal deposit;

    public User() {}

    public User(String username, String password, Role role, BigDecimal deposit)
    {
        this.username = username;
        this.password = password;
        this.role = role;
        this.deposit = deposit;
    }

    public int getId()
    {
        return userId;
    }

    public String getUsername()
    {
        return username;
    }

    public void setUsername(String username)
    {
        this.username = username;
    }

    public String getPassword()
    {
        return password;
    }

    public void setPassword(String password)
    {
        this.password = password;
    }

    public Role getRole()
    {
        return role;
    }

    public void setRole(String role)
    {
        this.role = Role.valueOf(role);
    }

    public void setRole(Role role) {
        this.role = role;
    }

    public BigDecimal getDeposit()
    {
        return deposit;
    }

    public void setDeposit(BigDecimal deposit)
    {
        this.deposit = deposit;
    }
}

Role enum:

public enum Role
{
    BUYER("buyer"),
    SELLER("seller");

    private final String role;

    Role(String role)
    {
        this.role = role;
    }

    public String getRole()
    {
        return role;
    }

    public static Role getRoleEnum(String roleString)
    {
        return switch (roleString.toLowerCase()) {
            case "buyer" -> Role.BUYER;
            case "seller" -> Role.SELLER;
            default -> throw new IllegalArgumentException("Role [" + roleString
                    + "] not supported.");
        };
    }
}