If you have to hand in a document, the instructions from your school or college will be shown above the submission field (or fields).
For each file that you have to submit, the submission field shows you what types you can hand in and whether submitting the file is mandatory or optional. You can drag the file that is to be handed in to the correct submission field. You can also click the submission field and select the file you want to hand in from your computer.
It is also possible to add explanations if you want, at the bottom of the submission fields.
When a mandatory file (or files) has been uploaded, the ‘SUBMIT’ button turns blue. Your work is only actually handed in when you press the ‘SUBMIT’ button, though. Until that point, you can still delete the work you uploaded and upload another file instead.
It may be the case that your school or college also asks you for confirmation upon handing the work in that you have not plagiarized or committed fraud or anything like that. If you tick that and use the ‘CONFIRM SUBMISSION’ button, you will have definitively handed in your work.
Depending on how the school has set it up, this activity may now have been completed. It is also possible that the teacher may give the assessment as part of the same activity. If the teacher gives a failure grade or rejects your file, they can give you another attempt in this step. You can upload and submit a file again for this new attempt.
There is also the option that the teacher notices you uploaded the wrong document and they allow you to resubmit a document. You will be notified when this occurs.