Build a Plane is an experience on the Roblox platform where you use different blocks to build a plane that you can fly to ...

Some other executors include: krnl, Fluxus, Script-Ware, Script-Ware M, and Synapse. Once the download is complete, install the Roblox Executor and open and log into it using your Roblox account.

If KRNL-Injector failed to find the Roblox process, delete KRNL App data and see. If that doesn't help follow the solutions mentioned in this post to resolve the issue.