Thanks for the pictures! So this is a threaded cap? Are you designing this is Fusion 360?
The “top surface consists of two parts” I do not understand. You are having the slicer show you two parts when you put it on the ‘bed’ in the slicer??
Drying - As @Thrawn said, the AMS can help keep filament dry, but it is not a dryer.
Some filaments like PETG or any Nylon blends will absorb moisture from the air. Some Nylon can become compromised in as little as a few hours!
Filament that has too much moisture can exhibit many problems when printed - poor finish, bad layer adhesion, bad surface quality, and if there’s enough water in it it will pop bubbles as printing, scarring the print!
The solution is long slow heating, preferably in a low humidity environment. PETG usually needs 60-65°C for 4 hours, but it varies by maker as all the plastics we use are blends and each varies.
Most people purchase and use a Filament Dryer or Dehydrator to drive moisture out of the filament. Many others use an oven of some sort. It must have an even temp and very accurate temperature control. Gas ovens are a problem since burning gas creates H2O as a byproduct.
One you have dried the filament it must be kept in a dry environment like the AMS or a thick sealed bag with desiccant. Note that every time you open the AMS you let in whatever the room air is. It takes hours or overnight to dry down inside the AMS, so try to plan your filament changes.
Here’s an article to help understand: