OK, so let's say my next print is that spool tray that
@Arbutus showed us.
Some filament needs to be dried before use. If you live in a soggy climate, it takes less than a couple of days for your dried filament to suck up enough water to cause problems.
So the filament goes back in the dryer for another 6 hours...
This is my gadget to keep the dried filaments dry for weeks at a time.
Its an open tray with a slot to hold a cheap hygrometer. The tray is loaded with an indicating dessicant which changes from orange to green when it is exhausted.
The filament is dried in the AMS or dryer as usual, until the humidity reads below 10%, then sealed in the...
How do I go about printing that tray? Should all of this be obvious? I assume I load his "DessicantTray.f3d" into the printer somehow, but it's not obvious to me how that is done. I had a good look at the Android Bambu Handy app that I installed during the setup. But I see no way to upload a file to it.
Or am I solidly opening the door to the big bambu bamboozel? I upload to my account at bambu and then print from there?
Or is this the place I've heard about where you put the file on a thumb drive and stick it into the printer USB port and then print from there?
OK.
Have you got a connection from your PC to the printer via the Bambu desktop application? Should be here:
"C:\Program Files\Bambu Studio\bambu-studio.exe"
You can put an icon on the desktop:
When you run it you get this:

You select what model printer and the type of print bed. Smooth or textured. They usually come with textured.
When you click on the sync info it will read the RFID tags on the reels in the AMS and fillin the filament list. #1 will be the default printing choice.
Anyway, File, import, the STL file is usually easier if the 3MF was meant for a different printer. This way it uses the default values. When the desiccant tray is loaded it's on its side. So you select rotate enter 90 degrees. If it's the wrong direction enter 180 to flip it over.
Next with the item highlighted with the solid line do a right click or Ctrl-K and clone one more so you can print two of them. (if you want to try that right away).
To arrange them for better printing motion select the 4th from the left to arrange the parts. Makes sure none are sitting on top of each other.
Now if you right click again on each item you can change the filament from the default slot #1. Easier to do that before you clone them.
Above is an example of PETG RED. The click on the slice print button on the top right

And we see it will take about 3 hours to print this. So now click on send the print plate button.
If it's the first time you are using this filament between power cycles set flow dynamics on and bed leveling on. Although theoretically the Bambu filament doesn't need the flow dynamics where some other cheaper PLA will.
Once you've done one print you can set all three switches off. Click on send.
At that point it will tell you that it's being sent through the cloud to your printer and assuming you have all that network stuff connected it will start heating the bed and then the extruder and then load the filament and do the prelim stuff.
If you've printed the benchy you've already done a lot of this.