так, ну на логин перебрасывает :_)

backend/src/main/java/com/example/backend/favorites/repository/CrudRepository.java

@@ -1,5 +0,0 @@
-package com.example.backend.favorites.repository;
-
-public class CrudRepository<T1, T2> {
-
-}

backend/src/main/java/com/example/backend/users/api/UserDTO.java

@@ -1,5 +1,6 @@
 package com.example.backend.users.api;
 
+import com.example.backend.users.model.UserRole;
 import com.fasterxml.jackson.annotation.JsonProperty;
 
 import jakarta.validation.constraints.NotBlank;
@@ -13,14 +14,14 @@ public class UserDTO {
 
     @NotBlank
     @Size(min = 2, max = 50)
-    private String username;
+    private String login;
 
     @NotBlank
     @Size(min = 2, max = 10)
     private String password;
 
     @NotNull
-    private boolean isAdmin;
+    private UserRole role;
 
     @JsonProperty(access = JsonProperty.Access.READ_ONLY)
     public Integer getId() {
@@ -31,12 +32,12 @@ public class UserDTO {
         this.id = id;
     }
 
-    public String getUsername() {
-        return username;
+    public String getLogin() {
+        return login;
     }
 
-    public void setUsername(String username) {
-        this.username = username;
+    public void setLogin(String login) {
+        this.login = login;
     }
 
     public String getPassword() {
@@ -47,11 +48,11 @@ public class UserDTO {
         this.password = password;
     }
 
-    public boolean getIsAdmin() {
-        return isAdmin;
+    public UserRole getRole() {
+        return role;
     }
 
-    public void setIsAdmin(boolean isAdmin) {
-        this.isAdmin = isAdmin;
+    public void setRole(UserRole role) {
+        this.role = role;
     }
 }

backend/src/main/java/com/example/backend/users/repository/UserRepository.java

@@ -6,7 +6,5 @@ import org.springframework.data.repository.CrudRepository;
 import com.example.backend.users.model.UserEntity;
 
 public interface UserRepository extends CrudRepository<UserEntity, Integer> {
-    Optional<UserEntity> findByUsernameIgnoreCase(String username);
-
     Optional<UserEntity> findByLoginIgnoreCase(String login);
 }