Hi Tony - that trigger is for the older Lencarta studio lights (and the Safari II location light) - it's not a generic trigger - the receiver units plug in to a dedicated socket on those lights.
Your light should work with any basic centre-pin trigger such as those you found in post #4. Those Hahnel ones are very expensive for a basic trigger though - you should be looking at about £15 to £30 for basic trigger and receiver. (Looking at images of the A7RII hot shoe it appears to have a centre pin).
eg:-
Shop Neewer 16 Channel Wireless Remote FM Flash Speedlite Radio Trigger with 2.5mm PC Receiver for Canon, Nikon, Olympus, Pentax, Sigma, Sunpak, and Other Flash Units. Free delivery and returns on eligible orders.
www.amazon.co.uk
or
Free delivery and returns on eligible orders. Buy JJC Wireless Remote Flash Speedlight Trigger for Sony Alpha A7III A7II A7 A7RIII A7RII A7R A7R2 A7SIII A7SII A7S A9 A6500 A6400 A6300 A6000 A5100 RX100 VII VI VA V IV III RX10 IV III II(2 Receiver) at Amazon UK.
www.amazon.co.uk
For TTL - you'll need a trigger/receiver pair, and a flash that understands the Sony TTL protocol. Your flash does TTL on the camera, so should work ok if the receiver you mount it on is emulating the camera hot-shoe. Lencarta do sell what you need:-
Godox X1R-S receiver for Sony
<h1><span><span>Godox X1R Wireless Flash Receiver</span></span></h1> <p><b>Main Features</b></p> <h1><span><span></span></span></h1> <ul> <li>BUILT IN 2.4G WIRELESS TRANSMITTER: The godox X1R receiver has a built in wireless 2.4G transmission system allowing you to use both a trigger and...
www.lencarta.com
Godox X-Pro-S controller for Sony
https://www.lencarta.com/godox-xpro-bundles
or
https://www.lencarta.com/godox-x2t-ttl-hss-bluetooth-wireless-2-4ghz-trigger
I prefer the X-Pro for the larger screen, however the x2t also has Bluetooth and works with your phone camera (if you like that sort of thing
)
They are also available via Amazon, eBay etc. Just make sure you get the Sony versions of both. This controller would also allow you to control any of the current Godox lights (all of which have built in receivers, and high capacity lithium battery packs, rather than quaint old AA cells))