I am trying to create a map in OpenLayers. I have no problem with other APIs, but the map style is old. Also, there is another application named Snap (it's using OSM) that has a prettier style:
How can I change OpenLayers map style?
You have to change the layer being displayed or the map. Different API's provide different layers that might have multiple styles.
For example here: https://cloud.maptiler.com/maps/