Something doesn’t look right in the construction of your A6. Where did you get it from? Here is the Banggood page for the BLF A6. You can see some pictures of it taken apart. It is different than yours internally.

BLF A6 at Banggood

EDIT: Just now realized, you do have another section to take apart. That part with the driver in it is a separate piece from the battery tube and can be unscrewed from it.