How to attache pergola posts to deck

[FemDiy]

Hello, I've always reserched this site for answers, but this is the first time for posting a thread.
Hubby & I have built a deck, free standing, and now want to add a pergola. I've found 'Pryda Bolt Down Post Anchors', description of the product says used for locating posts onto existing deck.

Has anyone used these? if so any advice? Are they strong enough to support one side of a 6m x 3m pergola? 3 posts in total on the rear side.

Or are we better to cut into new deck and either dig new footings or attach to existing posts & Bearers.
Thanks in advance for any posts

[watson]

You may find a bunch of "Deckies" on our sister forum Renovate Forums
Lots of deck stuff there.

[FemDiy]

thanks, have reposted