Source

File: wp-includes/rest-api/endpoints/class-wp-rest-block-directory-controller.php

protected function find_plugin_for_slug( $slug ) {
		require_once ABSPATH . 'wp-admin/includes/plugin.php';

		$plugin_files = get_plugins( '/' . $slug );

		if ( ! $plugin_files ) {
			return '';
		}

		$plugin_files = array_keys( $plugin_files );

		return $slug . '/' . reset( $plugin_files );
	}