A seal on the page says 100% risk-free, while the FAQ attaches conditions to the guarantee.
The FAQ says the guarantee runs 60 days from purchase and asks for at least 30 days of consistent use before you contact support. Risk-free is a marketing summary of that process.
Keep your order confirmation, track the dates, and contact support inside the window. Shipping costs and exact refund steps are in the refund policy, which is the document that governs.