I’m terribly sorry for the delay in responding to this topic.
You can find the API keys by logging in to https://usestrict.net/my-account and clicking API Keys. If you’ve already found it since and are having trouble activating, make sure to click Delete in the API Keys screen to clear previous activations. There seems to be a bug in the woocommerce api plugin that keeps disconnecting them. I’ve reached out to the authors to try and get it fixed.