If your teacher flagged your document, you can use the version history to show that you made changes and edits over time, which can indicate that you wrote it yourself. Check if your document is stored in a cloud service like Google Docs, as it usually keeps a record of all the changes made to the file, including the date and time. You can then share this version history with your teacher to demonstrate that you worked on the document over a period of time, making revisions and improvements, which can help prove that you didn't just generate it with AI.