fixed create backup command.

src/main/java/edu/stanford/protege/webprotege/project/CreateBackupOwlFileActionHandler.java

@@ -24,7 +24,7 @@ public Class<CreateBackupOwlFileAction> getActionClass() {
     @NotNull
     @Override
     public CreateBackupOwlFileResponse execute(@NotNull CreateBackupOwlFileAction action, @NotNull ExecutionContext executionContext) {
-        projectBackupManager.createBackup();
-        return new CreateBackupOwlFileResponse();
+        String backupFileLocation = projectBackupManager.createBackup();
+        return new CreateBackupOwlFileResponse(backupFileLocation);
     }
 }

src/main/java/edu/stanford/protege/webprotege/project/CreateBackupOwlFileResponse.java

@@ -1,11 +1,12 @@
 package edu.stanford.protege.webprotege.project;
 
+import com.fasterxml.jackson.annotation.JsonProperty;
 import com.fasterxml.jackson.annotation.JsonTypeName;
 import edu.stanford.protege.webprotege.common.Response;
 import edu.stanford.protege.webprotege.dispatch.Result;
 
 import static edu.stanford.protege.webprotege.project.CreateBackupOwlFileAction.CHANNEL;
 
 @JsonTypeName(CHANNEL)
-public record CreateBackupOwlFileResponse() implements Result, Response {
+public record CreateBackupOwlFileResponse(@JsonProperty("owlFileBackupLocation") String owlFileBackupLocation) implements Result, Response {
 }

src/main/java/edu/stanford/protege/webprotege/project/ProjectBackupManager.java

@@ -25,7 +25,7 @@ public ProjectBackupManager(ProjectDirectoryProvider projectDirectoryProvider, P
         this.backupDirectoryProvider = backupDirectoryProvider;
     }
 
-    public void createBackup() {
+    public String createBackup() {
         String currentDate = LocalDate.now().toString();
         Path sourcePath = new File(projectDirectoryProvider.get().getAbsolutePath()+ "/change-data/change-data.binary").toPath();
         Path targetDir = new File(backupDirectoryProvider.get().getAbsolutePath() + "/" + currentDate).toPath();
@@ -37,8 +37,10 @@ public void createBackup() {
             }
 
             Files.copy(sourcePath, targetPath, StandardCopyOption.REPLACE_EXISTING);
+            return targetPath.toAbsolutePath().toString();
         } catch (IOException e) {
             LOGGER.error("Error saving the backup file occurred", e);
+            throw new RuntimeException("Error saving the backup file occurred", e);
         }
     }