Can you get a butt augmentation from PRP injections combined with vacuum cups?

In one word, NO!  Do not believe any of this marketing bogus and attempts of unqualified personnel/physicians trying to get into the rapidly growing business of buttock enhancement surgery.  Like any booming fad or fashion, there are always scammers looking to get a peice of the action and make quick/easy profits.  Well as the saying goes, "anything too good to be true, usually is (not true)". Unfortunately the ripe new world of buttock augmentaion has become the next victim with a bunch of nonsense magical creams, potions, lotions and pills...NONE OF WHICH WORK AND ARE NOT FRAUGHT WITH SERIOUS SIDE-EFFECTS/COMPLICATIONS. It is not yet possible to take a substance that will only and exclusively makes your derrière grow. Other than being genetically blessed in the buttock and/or performing consistent rigorous exercise, there is no "natural" way to grow the buttock other than surgery.

It is very difficult to determine the exact size and shape implant you will require to best match your ideal butt image without an examination by a board certified plastic surgeon. Not just any board certified plastic surgeon, but one with many years of frequently performing breast augmentation surgery including different approaches, techniques and implant choices. This is because several measurements not to mention your breast characteristics are needed to determine the optimal implant size to obtain your goals. Without knowing these dimensions it would be difficult to make this determination. For example, the existing base width of your buttock will determine, in many cases, the maximal volume per implant profile that you can accommodate. Liposuction of your lower back and fat transfer is also helpful as an adjunct to implants. Using “want to be” photos however are useful if simply provided to the surgeon.

There are many websites that advertise techniques that are not effective. It is sometimes difficult for the consumer to judge what is useful and what is not since the presentation may be very convincing.
The standard technique for buttock augmentation which is now widely accepted and successfully practiced all over the world, is fat grafting. While other techniques may become available, you don't want to be a guinea pig for some new procedure that is not established.

I would suggest the best way forward for a surgically augmented butt is either fat grafting or an implant. PRP is good for skin rejuvenation and hair loss treatment and not much else. Please ensure you see a reputable PS to discuss your options.

When something sounds too good to be true, it often is.  PRP injections in my opinion is a bit hocus pocus.  Fat injection or implants are the only way too go.