You can apply both your Eats Pass benefits and promo code on the same order. If you are applying multiple benefits, the system would deduct Eats Pass benefits first and then deduct the promo code benefit.
For example: If the promo code contains a reduction on delivery fee and the order price (without delivery fee) is under NT$199, the promo code will apply. If the order price is above NT$199, Eater Pass benefit (NT$0 delivery fee) will apply.
As long as the order price is NT$199 and above (without delivery fee), all promo code application, and Eat pass benefits will apply.