The next step is to cover the edges with a fibre-tape to prevent cracking later when the mud dries.
The "mud" is actually white, and it's like poly-filla. We use it from a 5 gallon bucket, we use a lot of it. You also get it in dry powder form, mix with water and use, but like this is the easiest. Open the bucket, use what you need, close the bucket. Bucket lasts for weeks when sealed.
I didn't get a pic of the mud covering the patch unfortunately. I got called to go sort out a water issue at a house, so was in a hurry and fprgot. I'll try remember tomorrow. I use a 10-inch wide "spatula" to apply the mud. It's nice and wide so that I can cover a big area fast, and I get a nice even smooth finish. Makes sanding easier.