When I create a store, the chat come up like this.

And it comes up on the server cmd like this.

I'm sorry that I can't English.

According to the error, it appears that the server process is missing the necessary write permission in the plugins/Shopkeepers/data folder in order to write the save file.
This is something that the plugin cannot 'fix', but you have to configure your file system in such a way that the server process can write to the mentioned folder.

According to the error, it appears that the server process is missing the necessary write permission in the 에러에 의하면, 서버 프로세스에 필요한 기입 권한이 없는 것 같습니다.plugins/Shopkeepers/data folder in order to write the save file.폴더를 클릭하여 저장 파일을 작성합니다. This is something that the plugin cannot 'fix', but you have to configure your file system in such a way that the server process can write to the mentioned folder.이것은 플러그인으로 해결할 수 없지만 서버 프로세스가 언급한 폴더에 쓸 수 있도록 파일 시스템을 구성해야 합니다.

I'm sorry. I don't know how to do it.

I'm sorry. I don't know how to do it.

I can't really help you with this either. You have to figure out how this works for your specific operating and file system. Usually, the server process is run as a specific user, and folders/files are associated with specific read/write/execute permissions for different users or user groups (https://en.wikipedia.org/wiki/File-system_permissions).