Accessing Metabox values using JSX for custom Gutenberg Block

Hello, I have been creating a Gutenberg Block where the user can select a “Representative” (a custom post type) that they created from a dynamically generated <SelectControl>. All the information in the custom post type “Representatives” is stored within custom metaboxes.

Once the Representative is chosen from the dropdown list, it will populate the gutenberg Block with all the information associated with the post (Name, Position, Biography, Headshot, etc). It will also display this information in a styled card.

In order to complete this I need to be able to access the metabox values, but I can only find out how to do this through PHP. How can I access the metabox values using JSX and React, which is what the Gutenberg Block is being built with?