Basically what im asking is how do people on youtube who use PPD hit triple/double notes? Can I have the key combo or maybe some information on this? Thanks.

Well, they just hit 2/3/4 buttons simultaneously, there's no macroses like in Future Tone for PS4.

As for controls, some players write the keys they playing with on their PPD profile page, so you can just check it and see.

Or, if you mean you cant press several keys at the same time, so you getting WORST on those, there can be several reasons causing this with several solutions.

I can't hit 4 multiple notes with my keyboard (3 or lower works fine) and with ps4 pad 4 notes hit works fine). Any syggestions for fix this problem?
Thanks

Just change the key config i use two key in here: 1st satha here is:tringle,square,x,o, L, R
z x <, /, shift left,shift right
2nd kazzune is:tringle,square,x ,o, L, R
z, x, down, right, shift left,number 0
thats all my config i use

Thanks for sharing your setup.
But my problem is that my PC doesn't take the 4 keys input (I've tried 4/5 times and I'm sure I hit the right keys).
Even changing key configuration, it doesn't work.

(Ps: sorry for bad english!)

Some keyboards dont allow to press more than 2/3 buttons, so you might have to buy a better keyboard.
Maybe there's s software to press several buttons simultaneously...
Also be sure to turn off StickyKeys, those can screw your play as well

By the way, use this page to see what combinations you're able and not able to press (click on the small keyboard on the top and start to press bttons on your keyboard)
(https://www.microsoft.com/appliedsciences/content/projects/KeyboardGhostingDemo.aspx)

Thanks for the answer!
I tried my keyboard in the link you post and apparently my Laptop keyboard doesn't recognise 4 or more key simultaneously :/
To fix this maybe I can use some software for macro but I didn't find anything that can help me for this problem.

Better check again!

Thanks again for now ;)