Give your product away for free to people with a high/medium social media influence in a niche area and ask them for their feedback. Another way is to sponsor these (micro) influencers to post your product on their channels, or even hire them for long-term relationships as brand ambassadors. Since they have a positive reputation, people tend to associate this positivity with anything else they are involved with. This cognitive bias is called the halo effect. Source - DigitalPsychology.io
You can display their feedback in the header/announcement bar or below the add to cart button to improve customer trust and conversions.