I don't believe the decoder/controller will work with WS2812b strips.
It seems to have 4 outputs for GND, RED, GREEN, BLUE.. where the WS2812b strips have 3 outputs for GND, DATA, 5V connections..
30 channels of DMX is not nearly enough for LED pixels. Each LED on a strip of RGB WS2812b needs 3 DMX channels EACH (1-red, 1-blue, 1-green) - if you have 1m of WS2812b at 60leds/m - that's 90 DMX channels you need just for that 1m of leds.
Depending on how much LED length you require, finding an appropriate decoder/controller will be the biggest challenge. I've opted with an ARTNET solution with 6 universes (3072 DMX channels) to control my LED strips.