I’m the developer of the plugin and I can assure you there IS a free version. Can you please share why did you get the impression there isn’t? So we can fix that wrong impression for future users.
Did you read the email? It tells you that after 7-day of business plan trial your account would be downgraded to the free version. It doesn’t say you won’t be able to use it. And if you open the pricing, the first thing at the top of the page describes the free version details.
I’ll clarify again – we have 100% free version, and most of our users are using it without paying us a penny.