Getting Timers plugin to work with pet abilities

Hello! I've seen various videos of Beastmasters and they seem to have ability timers for all their pet moves such as razor fang. I can't seem to get this to work in my windower application. I tried to do some research and saw it posted somewhere to type //load windower.ffxi.get_abilities() from within the game. When I do that it just says file not found. Can someone run me through this please. I'm a bit of a pc noob. Thank you!