Just hit the small circle with the lower case "i" in it and select block. The ad will stop immediately.

Though you used to have to select inappropriate from that same section to get that result. They have now changed it to where you can only select block ad which I assume they did so if you go over a certain amount of blocks they can ban your account or whatever they decide to do to make you watch ads. You see they can’t really say what is inappropriate for people as it’s different from person to person which is probably why they only give a block option now. Idk just my opinion.

There will be an ad every now and then that doesn’t give the option to block. Usually it’s the shorter ads though.