Most commercial suppressors are ridiculously expensive for what they do, silence the muzzle sound.
The Donny FL suppressors (in the $100 to $200+ range) cost as much as an entire air gun.
To make a suppressor you need:
-baffles (3D printed, or made from various other materials). I use the baffle from the Crosman Nitro Piston rifles which costs above $2,
-tube (plastic/PVC works very well for airguns) which holds the baffles. I use a 1" ID thin PVC tube.
-adapter to fit to the rifle barrel/shroud to the above tube. I mostly use duct tape to shim the above tube or Crosman baffle.
Making a suppressor is not hard.
I made my own suppressors for several air rifles and each cost less than $3-$4 in materials.
The simplest suppressor you can make will be a tube with one end attached to the rifle barrel/shroud and the other end covered with duct tape (acting as a baffle).
It will significantly reduce the sound, the more tube volume (longer/ticker tube) the more the sound will be reduced.