Mount 77" TV hanger on dry wall that has steel studs

I have a 77" Samsung tv weighing 34kg and i want to mount it on my wall. The wall is dry wall and has metal studs, not wooden! i have a One For All tv hanger model WM6619 that i want to use. It has 4 horizontal holesm i need someone with experience with mounting on metal studs and knows what screws and plugs are best for this work. i can buy the screws and plugs. i have my own drill. i have Bosch Truvo Easy digital detectot, but if you have a better one, that's even better. Here is what the building documentation says about the wall and mounting TVs: partition-wall Apartment partitions are made up of plaster and insulated steel studs according to solutions that comply with current sound and fire requirements in apartment dividers, respectively. 55dB and ei 60. In the walls there are technical guidelines such as electric cables and water pipes. Sliding doors have frames inside the walls. It is therefore important to ensure that there is no conflict with these things when attaching or hanging equipment on the wall. Heavier equipment such as flat-screen TVs must be attached in studs.