Every project in Avocode has an export path. That means every image asset you export from any design in this project will end up in the folder you've set up. We always ask what's the export path the first time you export anything. You can of course edit this path later in the Settings of the Desktop app.
Open up the Settings and find the project in which you'd like to change the path. Choose a path and confirm. Any future exports will be saved in a new folder.