hoppscotch/packages/hoppscotch-app/assets/icons/maximize-2.svg

<svg xmlns="http://www.w3.org/2000/svg" width="24" height="24" viewBox="0 0 24 24" fill="none" stroke="currentColor" stroke-width="2" stroke-linecap="round" stroke-linejoin="round">
  <polyline points="15 3 21 3 21 9"></polyline>
  <polyline points="9 21 3 21 3 15"></polyline>
  <line x1="21" y1="3" x2="14" y2="10"></line>
  <line x1="3" y1="21" x2="10" y2="14"></line>
</svg>