In order to export visualization from Compose, go to the Export button which is located at the top right corner of Compose.
The Export feature includes combined options for PPTX, PDF, Excel and JSON.
The file format is set to PowerPoint by default.
To export PDF instead, select the PDF option from the Format selector.
Once the export is triggered, you can check the progress in the menu opened with an arrow next to the download icon. There you can see which exports are still in progress and which are ready (and click on the file to download it), clear the list of ready/ queued exports, or download all. The export icon will show a counter if there are any actions available, i.e., any exports either in progress or ready to be downloaded.