Unfortunately, there is no possibility to search or enter specific coordinates directly. However, it is possible to show your own custom coordinates on the Star Map. You first need to deselect the option "show coordinates" and then under "additional options" you can insert your own coordinates in the "customize location" field. This will replace the name of the location selected initially. 

Please note that the constellations shown will still be the one of this location so for more accuracy, make sure to choose a location close by.