Open the "Administration" menu, Select the option "Add-ons". On the left hand side menu, you can find "Import projects".
The dropdown menu "Project file type" allows you to choose whether you want to select Project Configuration only (XML), or Complete Project (ZIP).
When importing project configurations, click Browse and choose your XML file from the file system.
When importing a complete project, you can switch between two options:
Browser upload gives you quicker access to proceed to import since the user doesn't have to access servers. Project Configurator uses browser upload as default way of getting your ZIP file to Jira.