When you're ready to submit something to codePost, navigate to https://codepost.io, log in, and find the assignment you're interested in. Then click click the green "Upload assignment" button in that assignment's row.
When you click this button, you'll see a pop-up window that looks like this one:
Submitting work
Click the upload files button to add files. You can upload files individually or upload a .zip file containing multiple files. Make sure you upload all required files. If you don't, you won't be able to submit.
Click the Tests tab to view any tests your instructor has written for this assignment. If you don't see this tab, then your instructor hasn't written any tests for you to use. If you've submitted previously, you'll see your last submission's results from this tab.
When you're ready to submit, hit the Upload button at the bottom right of the window. If it's disabled, make sure you've added all required files.
Viewing past submissions
If you've submitted to an assignment, you'll be able to see the last submission you made by clicking on the Most recent submission tab.
Also, you can see the test results from your last submission by hitting the Tests tab.
Adding partners
If you're working on a group assignment, follow these instructions to add your partners.
Submitting late
If you want to submit after an assignment's due date has passed, your submission will be marked as late. You'll only be allowed to submit late if your instructor has enabled the appropriate assignment setting.