Mix C well, strain, and set aside. Marinate fish with 1 tsp salt and set aside.
Blend A in a food processor until fine. Heat 3 tbsp oil in the Instant Pot inner pot using the Saute function. Stir fry A until aromatic, add in B stir-fry a while. Cancel saute mode.
Pour C into the inner pot and mix well. Follow by onions, tomato, and pineapple,
Add the lady fingers, brinjal & green chillies. Place fish on top of the vegetables. Cover with the lid. Select steam mode on Low Pressure for 5 mins. Quick release pressure when done cooking.