I created a real quick tutorial showcasing how to add the SendFox API to Thrive Themes API Connection.
As a refresher, SendFox offers straightforward marketing "automations" in the form of sequences that can be time-delayed or triggered by adding someone to a list (think tags).
Using the Thrive to SendFox API, you can simply choose SendFox as the API connection, choose your "list" from the drop-down, and you're ready to go.
If you're looking for more information about SendFox, I highly recommend you check out my review/overview of the platform. It's a great place to start your email marketing journey for just a $49 one-time fee. If you'd like to remove double opt-in, SendFox branding, and gain access to a higher-quality sending server then you can upgrade to the "Empire add-on" for $10/month.
If you have any questions about the SendFox API integration or SendFox in general, I've become quite an enthusiast for the platform and I'd be happy to point you in the right direction.