Are you referring to a fixed price contract? If yes, you will need to submit the work on the milestone created for you. After 14 days the funds will be transferred to your account if no actions are taken on the milestone. Keep in mind that if you resubmit the work again you will reset the 14 days period. To learn more details about fixed price protection, check out this Help Article. Thank you.
As long as you used the "Submit Work" button on the contract page, you don't need to do anything else. The client has 14 days to review the work. If they do nothing, you'll be paid anyway, assuming the escrow was funded when you took the contract.