Yith Gift Cards problem

Good morning,
I’ve installed the plugin Yith Gift Cards on my website (in the same way that I?d installed at others websites) but now, the plugin doesn’t offer the fields and the button to complish the process.
I write you a public url with the gift card applied to understand it better: https://conchajuan.com/producto/hialuronico-bono-regalo/
Please, could you tell me why is occuring this?
I have an example with your same plugin that runs correctly. Is the next one: https://farmaciacid.com/product/tarjeta-regalo-bebes-y-mamas/

Thanks I hope your answer as soon as possible.

The page I need help with: [log in to see the link]