If the project is still “assignable”, you first need to accept the project by clicking on the Accept Project button.
You will be given some seconds to review the details about the project and then confirm your acceptance. Once you've confirmed your acceptance of the project, you will have a designated amount of time to submit your deliverable, and a visible timer will appear that will help you track how much time you have left.
You must submit your file within the time limit. When the time limit is reached, your crafting session will expire and the project will become “assignable” for another Pro to claim. Please keep in mind that your deliverable must be an edited and finished file.