GDPR page is a must as said above, however i will assume you are changing that.
Fist of the tabs o the bottom of the website, you can go to a secomd tab but it has no title , read more or anything. Dutch people dont only google in dutch and outsiders cant translate your website, you need a English sub directory or sub domain and make use of it via geo targeting at least offer the option.
You have some sort code stick out on the second tab page one. As im going though I see you have added the consent for cookies.
I cannot judge much about content as the language is not mine, however i dont see a clear sales funnel , your modal for more details are broken , do not show more images and the text is the same is that on main page, so i assume you just copied it, i was expecting more information with the eyeball button... in depth information as somebody who has now used a click to satisfy my query... it was not instead i find copied text a broken modal, if i were a user i would bounce right here. I find all the details are are on the blue button which to me as a user indicates to the go to the cart...I did not click there as i had not made my decision on the product.... some of the blue buttons dont offer extra info and just add to cart....
Therefore i dont even think its necessary to crit the rest of the website.
Testimonials , ctas, site speeds, accessibility , the jpeg logo which should be a png because you have two blues now..........
Best of luck to you.