By default the maps will take 100% of the available width, until they reach the maximum width set in the visual setting page.
By default, the Max-Width value is set to 2000px. You can change this value if needed.
If your map is not taking 100% of the available width, these are the possible reasons:
The max-width value mentioned above is smaller than 100% of the available space;
The container where you place the map, does not have 100% of the available width;
If you place the map on a container that is not full width, the map also won’t be able to be full width. If you’re using a page builder, make sure the container where you place the map is also full width.
There might be themes that do not allow the content to take 100% of the width, in those cases you would need to make changes to the theme. The map itself can only be as big as the container where it’s placed.