Cover the patch and tape with joint compound, feathering the perimeters. Enable the compound to dry according to the producer’s Directions. Use a second coat if needed. Sand clean. Now you may need a piece of plasterboard to fill the opening. Preferably this must be thinner than the current plasterboard. https://linkedbookmarker.com/story3550555/the-buy-stainless-steel-banding-diaries