Read the log. It tells you everything you need to know and also gives you a link to the manual.
That looks like something you need to ask the people at the Yarn project about, but it seems you have some undefined values in your package.json - if Iām reading it correctly. It expects an author name and version or description.
GDevelop has built-in tools to work with Yarn and handles all the packaging though.
yep! but i cannot upload for reasons :< i did exactly these Instructions in this page ( Publish your game to Windows, macOS and Linux manually using Electron and Electron Builder [GDevelop wiki] ) but when run yarn electron-builder build script this error happen 
can some one give me a video to how package a gdevelop game manually ?
Your package.json is malformed. Look at the npm website for a correct package.json and correct it.
kidding me ?! the .json file include all events and is the heart of game that use sprits to create a game! packager must use gdevelop .json file but even when i replace gdevelop .json file with yarn .json file i see this error! idk about these scripts and offline packager so need some one to help me
json is a data format to export data commonly used in JS. The one used as project by gdevelop has NOTHING to do with the package.json file. The package.json is the file that contains infos on a javascript project to install dependencies using the yarn dependencies management tool or npm, or store informations like the developer name and software version required to compile to a PE file! If you replace your project file with your package.json, you can say that your project is dead. If you replaced package.json with project.json, no wonder it does not works!