According to the provisions of China's patent law, you need to make the design drawings meet the requirements according to the provisions of the law, basically adding a three-dimensional view on the basis of the front view, back view, left view, right view, top view and bottom view. Your design is a notebook case, so it is better to use two three-dimensional views, one is closed and the other is open.
After the drawings are completed, it will be very simple in China. Fill in an application for a patent for design (downloaded from China National Intellectual Property Administration), submit it to the agency in China National Intellectual Property Administration or other places together with the attached drawings, and pay the application fee within two months (individual applications are delayed, and the application fee is only in 75 yuan).
If you think your design is good enough and want to sell it to foreign manufacturers, you'd better apply for a patent abroad, such as pct application (indicate the United States and Europe, etc. ), or apply directly in the United States first. This needs the help of the company. The U.S. Patent Office does not directly accept foreign patent applications, but must go through an agency. Many domestic institutions have the ability to apply abroad (cooperate with foreign companies), and the cost is relatively high.
It is recommended to apply in China first, and whether to apply abroad depends on the market reaction.