Your Flock documents can be accessed from your account at any time and downloaded as PDFs.
Sometimes, pop-up blockers can prevent these documents from downloading and therefore, if you are having problems, it may be worth checking your browser settings as browsers often block 'pop-ups.' Here are a few links for how to remove pop-up blockers from your browser:
It is also worth checking the pop-up settings on your device as well, especially if you are using an iPhone. (Settings > Safari > Block Pop-Ups toggle)
When you click on the download button your browser URL may change to unlock the pop-up. If you are still having issues, you may have to try a different browser or use incognito/ private mode.