TPX Pantones

Hello, I'm trying to match colours to an existing image.

The image has pantone references in this format; 15-4421 TPX Blue Grotto. So far I've just been using the eyedropper tool but worry this isn't accurate enough. When I open the colour libraries, I'm olny given close options, but nothing exact. Do I need to downlaod a TPX pantone library, if this is a thing? Or is using the eye drop tool the best I can do?

Any help would be much appreciated!