Directly in the design interface, select the box in the page border. Below I will demonstrate the detailed operation steps:

(computer model: MacBook Air, software version: Word 202 1)

1. Open Word and click the design above;

2. Click on the page border in the upper right corner;

3. A light gray box pops up, and click the box;

4. Click OK in the lower right corner;

5. word add box operation is completed!

The above is a tutorial on how to add boxes in word, I hope it will help you ~