[Brezzalient]

Actually the 2019 Ignis comes with roof rails. If you weren't aware earlier, roof rails are used to carry bulky cargo or sporting equipment overhead that can use special roof mounts which can be fixed on to these rails.
They are a modern version of the old 'luggage carrier' except that they are designed to be mounting points rather than carriers. You can carry your luggage in special containers that use these mounts (Thule roof boxes, for instance).

 

[Brezzalient]

You can remove the roof rails but I remember a friend of mine removed the rails on the roof of his car and it leads to water leakage as it wasn't done properly. He was told a procedure where he had to locate the bolts joining the rails to the roof and then unbolt it. In case he was unable to locate the bolts he would have to take off the headline. But I guess what he forgot to do was seal the holes. I would suggest you rather to a mechanic to get this done perfectly.