Hi,
There is nothing to "fix". Recatpcha v3 is basically recaptcha v2 with on top of that the capability to get analytics on the risk of different actions on different pages of the website. So the recaptcha plugin we provide is already v3.
Should we made a v3 change, it would just be handling a score instead of true/false for the result of the captcha and you would have to setup a threshold setting in the plugin to authorize / refuse the scores based on it.
So it would just make it more complex to setup (as you would need to guess what score is best for your website), while it wouldn't add any benefit.
Now, another plugin could be developed for recaptcha v3 to add analytic capabilities and track the risk of the user among different actions of your website, and it could potentially be combined with the v2 plugin already there. But that's a complex development as you need to be able to define which actions you want to track on your website (so it needs to be dynamic and support Joomla actions, HikaShop actions, and other extension actions), and that also means that it would require a configuration of the actions to track on your website in the plugin.
In short, there is nothing to fix, and I would recommend to just use the plugin for what it's been made to do, since it does what it is supposed to do: look bots from registration on your website.