Create assignment with file drive using google apps script

I'm a new developer, I want to add an assignment in Google Classroom using a script. Here is the code that was created:

function assignmentWithDriveFile(){
  const ss = SpreadsheetApp.getActiveSpreadsheet();
  const sheet = ss.getSheetByName('ASSIGNMENT (Drive File)');
  const courseId = sheet.getRange('B1').getValue();
  const topicId = sheet.getRange('B2').getValue.toString();

  var assignment = {
    topicId: topicId,
    title: sheet.getRange('B3').getValue().toString(),
    description: sheet.getRange('B4').getValue().toString(),
    materials :[{
      driveFile: {
        driveFile: {
          id: sheet.getRange('B5').getValue.toString(),
          title: sheet.getRange('B6').getValue.toString()
        },
        shareMode: "STUDENT_COPY"
      }
    }],
    maxPoints : sheet.getRange('B7').getValue().toString(),
    state: "PUBLISHED",
    workType: "ASSIGNMENT"
  };

  const newCourseAssignment = Classroom.Courses.CourseWork.create(assignment, courseId);
  const assId = newCourseAssignment.id;
  sheet.getRange('D1').setValue(assId);
}

after running I get a notification in my spreadsheet that is "GoogleJsonResponseException: API call to classroom.courses.courseWork.create failed with error: @AttachmentNotVisible The item referenced by an attachment was not found or not visible to the user." well what should i do? I really wait for your answer and I appreciate it```

Do I have to change the drive ID?

Modification points:

• About the error of The item referenced by an attachment was not found or not visible to the user., in this case, when the file ID is the invalid file ID, such an error occurs. When I saw your showing script, I thought that at id: sheet.getRange('B5').getValue.toString(),, getValue should be getValue(). This can be also seen at title: sheet.getRange('B6').getValue.toString(). If your file ID is correct, I thought that the reason for your issue might be due to this.

• In your situation, I think that the values can be retrieved from cells B1:B7 by one call.

When these points are reflected in your script, how about the following modification?

Modified script:

function assignmentWithDriveFile() {
  const ss = SpreadsheetApp.getActiveSpreadsheet();
  const sheet = ss.getSheetByName('ASSIGNMENT (Drive File)');
  const [[courseId], [topicId], [title], [description], [driveFileId], [driveFileTitle], [maxPoints]] = sheet.getRange("B1:B7").getDisplayValues();
  var assignment = {
    topicId,
    title,
    description,
    materials: [{
      driveFile: {
        driveFile: {
          id: driveFileId, title: driveFileTitle
        },
        shareMode: "STUDENT_COPY"
      }
    }],
    maxPoints: maxPoints,
    state: "PUBLISHED",
    workType: "ASSIGNMENT"
  };
  const newCourseAssignment = Classroom.Courses.CourseWork.create(assignment, courseId);
  const assId = newCourseAssignment.id;
  sheet.getRange('D1').setValue(assId);
}

• I think that when these values of [[courseId], [topicId], [title], [description], [driveFileId], [driveFileTitle], [maxPoints]] are correct values, this script works.