What should I do if I can't take out the battery cover when replacing the battery of Xiaomi LCD Writing Tablet 13.5" (Color Edition)?

The battery cover of this product is designed to be removed with one hand to avoid the danger of easy removal by young children. Therefore, you need to use a tool to pry up the Therefore, you need to use a tool to pry up the side to remove the battery cover, as shown in the figure below.