Ender 3 Marlin Unknown Env Build Error

Hey all,

very new and unfamiliar with platoform.io and such (but not completely useless with a computer) - trying to build Marlin to increase bed size for a 3d printer. following a youtube tutorial (https://www.youtube.com/watch?v=so0FfFVEmiw) and have been with it step by step, using all the linked downloads, etc. until the clicking build

when i try to build it gives me an error, unlike in the video:

UnknownEnvNamesError: Unknown environment names ‘STM32F103RE_creality_maple’. Valid names are ‘include_tree’

I tried looking for a “STN32F10RE_creality_maple” in my files but couldn’t find anything. Not sure where to go or what to do, any help appreciated. Thanks.

Please zip + upload the exact project files you’re having problems with and upload them somewhere. (Goggle drive, Dropbox, wherever)