A different window pops up. Download the v5.28 HomeBrew Gen3 firmware image file, and then click on the "..." in the middle of the first table entry. Browse to the downloaded file, and enter its path into the Green area. Put a zero (0) in the smaller entry field to the right of it, and click the checkmark on the left. Down at bottom right, select the appropriate COM port for the HomeBrew/ESP32 from the drop-down menu there.
Use the magnify icons (above) to change the image size