Hi Balt_4238, welcome to our forum. umap is a platform separated from OSM. You can do in umap whatever the map allows you to do, save it for yourself or share it with others. It does not affect the OSM database.
Nevertheless if you see anything in the umap basic data which is apparently wrong please feel free to create an OSM account and correct it in the OSM database so that also other users may benefit from your work.