Let's click on the insert next to the beginning to add pictures here.

In the picture, we import our prepared handwritten signature.

Then we resize the picture.

Click the image tool to increase the transparency until it turns white.

Then we click it, click it again, and set the transparent color outside the background.

Place the mouse on the blank background in the picture and click the mouse.

We can see that the background has been removed. We just need to adjust the size.