How to do that hollow font?

1. Prepare text and objects to be hollowed out, such as pictures, and overlap them to adjust their relative positions:

2. Select a picture and text, cut and right-click the page, and then paste it as a picture selectively:

3. Select a picture, enter the picture format tab, use the "Delete Background" command, mark the picture with a retention pen and a deletion pen, adjust the deletion area to retain the picture, and delete the text part (this part takes time depending on the complexity of the background):

4. Click "Keep Changes" and the text will be hollowed out. Fill the page background with yellow to see the effect:

If you need to hollow out a solid color shape, it will be easier. After the text and shapes are selectively pasted into the picture, you can use the command of "Color-Set Transparent Color" to directly hollow out the text without "deleting the background" (but this requires that the background cannot be the same color as the text):

Above.