In the RegistrationRequest class files found an issue

src/main/java/com/example/demo/appuser/AppUserRepository.java

@@ -10,8 +10,7 @@
 
 @Repository
 @Transactional(readOnly = true)
-public interface AppUserRepository
-        extends JpaRepository<AppUser, Long> {
+public interface AppUserRepository extends JpaRepository<AppUser, Long> {
 
     Optional<AppUser> findByEmail(String email);
 

src/main/java/com/example/demo/registration/RegistrationRequest.java

@@ -1,17 +1,36 @@
 package com.example.demo.registration;
 
-import lombok.AllArgsConstructor;
 import lombok.EqualsAndHashCode;
 import lombok.Getter;
 import lombok.ToString;
 
 @Getter
-@AllArgsConstructor
 @EqualsAndHashCode
 @ToString
 public class RegistrationRequest {
-    private final String firstName;
-    private final String lastName;
-    private final String email;
-    private final String password;
+
+    //We have to remove the final from here to set the values
+    private  String firstName;
+    private  String lastName;
+    private  String email;
+    private  String password;
+
+
+    //We have to use this nowadays, if not we are going to face the
+    // [com-fasterxml-jackson-databind-exc-invaliddefinitionexception-cannot-construct-instance-of-xyz-no-creators-
+    // like-default-construct-exist-cannot-deserialize-from-object-value-no-delega/]
+    //I faced the error recently.
+    //I have used the strategy of default constructor.
+
+
+    //default constructor
+    public RegistrationRequest() {
+    }
+
+    public RegistrationRequest(String firstName, String lastName, String email, String password) {
+        this.firstName = firstName;
+        this.lastName = lastName;
+        this.email = email;
+        this.password = password;
+    }
 }