Instant Pot Triple Chocolate Fudge

Add 1 1/2 cups water to the Instant Pot insert and place the trivet inside.
In a medium heat safe bowl, combine the milk chocolate chips, semi sweet chocolate chips, 1/2 cup of the dark chocolate chips and the sweetened condensed milk.
Place the bowl on the trivet inside the Instant Pot.
Secure the lid and set the valve to sealing. Cook on High Pressure for 1 minute. Carefully quick release the pressure and remove the bowl from the Instant Pot.
Stir the chocolate mixture until completely smooth.
Stir in the butter and vanilla extract.
Add the milk, 1 tablespoon at a time, stirring between additions until the fudge becomes smooth, thick and glossy.
Line an 8x8-inch pan with parchment paper. Pour the fudge mixture into the prepared pan and smooth the top evenly. Let the fudge sit for 1 to 2 minutes so it cools slightly.
Sprinkle the remaining 1/2 cup dark chocolate chips over the top and gently press them into the fudge so they soften and become glossy without fully melting.
Refrigerate for 2 to 3 hours, or until firm. Slice into squares and serve.