Pour enough vegetable oil into a sturdy skillet (preferably cast iron) so it comes about halfway up the sides, being careful not to overfill. Heat over medium until the oil reaches 335 to 350°F.
Whisk together 1 cup all-purpose flour, 1 teaspoon Kosher salt, and ½ teaspoon black pepper in a medium bowl; set aside.
In another medium bowl, whisk together 2 large eggs and 1 tbsp melted unsalted butter until combined, then stir in 1 cup orange juice. Stir the flour mixture into the wet mixture until just smooth.
In a shallow bowl or platter, mix 3 cups sweetened coconut flakes and 1 cup Panko breadcrumbs.
One by one, dip the shrimp into the batter, then press each shrimp into the coconut–Panko mixture until evenly coated, leaving tails visible if they are still attached.
Carefully add the breaded shrimp to the hot oil and fry until golden, flipping halfway through (about 4 minutes total).
Remove the shrimp from the oil and drain on a plate lined with paper towels. Repeat with the remaining shrimp.
Serve the fried shrimp with Thai sweet chili sauce for dipping.