To export an alignment as image click the Export as image button on the editor toolbar.
The file save dialog will appear where you should set name, location, export settings and format of the picture:
UGENE supports export to the BMP, JPEG, JPG, PNG, PPM, TIF, TIFF, XBM, and XPM image formats. You can export whole alignment or custom region. To select the custom region click on the Select button.