The page describes HoneyFil as a one-time purchase, not a subscription, and in the same breath tells you to confirm at checkout. Here is how.
Read the order summary line by line. Look for a pre-ticked box offering a subscription or an add-on, an upsell offered after you enter your details, and wording like 'recurring' or 'auto-ship'. Open the terms link before you pay and look for the words one-time, subscription and renewal.
A page statement and the checkout can differ, and the checkout is what governs your order.
Save the confirmation email and a screenshot of the final total. Check your card statement over the following months for any charge you did not expect. If one appears, contact the seller first and then your card issuer, using the documents you saved.