1. First, start your correspondence and click Login, as shown in the figure below.
2. Secondly, go to the home page and click the "Function" option, as shown in the figure below.
3. Next, select Formula System and click Formula Manager, as shown in the figure below.
4. Then in the technical index formula, click other types, and then click New, as shown in the figure below.
5. Then, enter the formula name and formula content, as shown in the figure below.
6. Finally, enter the line drawing method, click to select the main image overlay, and then click OK, as shown in the figure below.