Display Screen or Portion Thereof with Graphical User Interface

The FIGURE is a front view of a display screen or portion thereof with a graphical user interface showing our new design. The dot-dash broken line rectangle illustrates a display screen or portion thereof and forms no part of the claimed design. All other broken lines illustrate portions of the graphical user interface that form no part of the claimed design. The grayscale tones which depict features of the graphical user interface are intended to represent a contrast in appearance, and form part of the claimed design.