You didn't mention the year of your 27RB. My 2021 Whitehawk 27RB came prepped for a Solera slide topper. Look right above the slider. You should see a long black rail and a Solera slide topper prep sticker.
Even if it's not prepped, the Solera slide topper comes with the same rail. The only difference is you would need to install the rail, which is not too difficult.
It is a two-person job just as the others have said. There are several good YouTube videos on the installation. It's not that difficult.
Be certain to carefully measure before you order. For the 2021 Whitehawk 27RB it required a
13'6" Solera Black Slide Topper Awning. Be sure to measure correctly, if you have any questions, contact Solera, they are very helpful and will answer any questions you have.