You should understand that not all graphics file formats support DPI setting.
If the format supports this setting, you may do the following:
- Select output format;
- Expand format settings (click on “+” icon located to the left of “Save images in …..” line);
- Below format settings, enter the needed value in “horizontal” box.
If you want different horizontal and vertical DPI, uncheck the option “Use as horizontal” and enter the needed value into “vertical” box.