In the image, there is a 3.5 mm audio jack port on top. (gizcentral.com)
From the picture, The USB Type - C reserves place for the 3.5 mm headphone jack port. (myfixguide.com)
Although the port covers are there to protect the tablet from water, we found them to be somewhat difficult to open, especially the headphone jack port cover. (laptopmag.com)