see a video and follow - it clarify alot of things on that form after my mistakes. Since your overseas - and IRCC request of you to fill out these forms, you are the principal applicant. when your doing the history, there should be NO GAPS, between months and years. each timeline should be picked up from the following month and year etc, my form was sent back due to those mistake. also, all forms especially some forms that doesn't allowed you to be sign them online, you should printed off form and sign it manually and scanned it clearly, preferable pdf format and upload.