Summary from https://www.foodnetwork.com/how-to/articles/how-to-grill-salmon-a-step-by-step-guide

Prep

For even cooking, you’ll want to let the salmon come to room temperature for 20 minutes before grilling.

Set the salmon on a paper towel-lined pan and pat dry. A dry surface speeds up the searing process and prevents sticking. If it’s marinated, blot off as much marinade as possible before grilling.

Right before placing it on the grill, lightly rub the salmon with olive oil on both sides, and sprinkle with kosher salt and freshly ground pepper. Always season fish just before grilling to avoid moisture loss and flare-ups.

Grilling

Make two cooking zones: a hot zone for searing and another for lower, gentle cooking. For a gas grill, turn the burners on one side to high and the other side to low. If you’re cooking with charcoal, push the hot coals onto one-half of the grill. The two zones will allow you to sear the salmon on the high-heat side, then transfer it to the cooler side to finish cooking. Close the lid and preheat for 15 minutes. This will burn off the oil and make the grill nonstick and very hot, about 500 degrees. For a charcoal grill, keep the lid vents open for air circulation.

1. Open the grill lid and place the salmon, skin-side down, on the hot zone. Most of the cooking will take place on the skin side. Allow 6 to 8 minutes, depending on the thickness.

2. Use a fish spatula to gently flip the salmon over onto the lower-heat side. If it sticks, give it another minute or two. When it’s ready, it will release easily. (Note that you should never use tongs to flip delicate fish.) Cook for an additional 2 to 4 minutes on the other side, depending on the desired doneness.

Salmon cooks quickly on the grill (usually no more than 12 minutes total), so don’t walk away or get distracted. The salmon will be medium-rare when an instant read thermometer inserted into the thickest portion reads 120 degrees F. Let it rest for a few minutes before serving to allow for some carryover cooking.