Microwave Steamed Fish

Name: Microwave-Steamed Fish
Ingredients: 1 1-lb. skin-on white fish fillet (such as sablefish, sea bass, or red snapper); 1 Tbsp. Diamond Crystal or 1¾ tsp. Morton kosher salt; 1 Tbsp. plus 1½ tsp. sugar; 1 1 piece ginger, peeled, cut into thin matchsticks; 1 Tbsp. light or regular soy sauce; ½ tsp. fish sauce; 1 scallion, cut into 2 pieces, thinly sliced lengthwise; 2 Tbsp. vegetable oil; Steamed jasmine rice (for serving)