How can I install a whole new key (keycap, hinge, membrane) on a 2019 MBP?

I purchased a replacement key on ebay: https://www.ebay.com/itm/293150670235?ssPageName=STRK%3AMEBIDX%3AIT&var=592358530513&_trksid=p2060353.m2749.l2648

The key comes with the cap, hinge, and membrane as a single piece. However, I'm unsure of how to make the key stay in place when I put it into my keyboard. The key fits and it works when I press it down, but it's not secured in place. The key can easily just come back out if I try to. Is there an adhesive of some sort I'm supposed to use to secure the hinge to the base of the keyboard?

From Apple:

Keyboard Service Program for MacBook, MacBook Air, and MacBook Pro

Give Apple a call and talk to them about this, they might be able to repair this in the store for you under this program.