Can the Apple Watch give accurate blood pressure?

There are options such as this:

Withings BPM Connect Wi-Fi Smart Blood Pressure Monitor - Apple

However, they don't really have anything to do with the Apple Watch. Most of the ones I've seen work with an app on the iPhone and sync the data to Health on your iPhone.

Apple watch can't measure blood pressure without an external hardware monitor and a compatible 3rd party app.

which hardware monitor and app?