thanks

(1) Open a new tab to about:config (type about:config in the Awesomebar and tap the go arrow or tap Enter)

(2) In the search box, type down and tap Enter

(3) Scroll down to browser.download.folderList and tap Modify, then change the value from 1 to 2 (from default always to last used folder). The change should appear after a few seconds.

(3) Scroll back up and tap the "Add a New Setting" button

(A) String is the correct type, so OK that

(B) The name of the preference should be browser.download.dir (this stores the last used directory)

(C) The value should be /sdcard/ followed by the folder name you want to use, for example, /sdcard/FxDown