Hey @albertsauque
Thanks for referencing the site domain for us. Looking at the products on your site I can see the ApplePay button displayed like in this example below on the desktop.
**Desktop**

Image Link: https://snipboard.io/fhJKgU.jpg
I don’t however see the ApplePay button displaying on my iPhone though.
I also noticed when testing that GooglePay is displayed on a desktop version of Google Chrome but not on a Smartphone too.
As it’s the exact same Expres payment buttons that are displayed on desktops and smartphones this indicates that potentially something isolated to your particular website site is preventing the buttons from displaying on smartphone devices.
I tested on one of my installations and could not replicate the same behaviour and both the Google pay and ApplePay buttons were displayed on smartphone devices.
From what we’re seeing, it could be code from another plugin or theme which has caused a possible conflict and affected the functionality of WooCommerce.
To see if that is the case we’d suggest carrying out a conflict test on your site by disabling all other plugins aside from WooCommerce along with switching to a theme like Twenty Twenty Two. This will help with trying to and locate what software you have installed which could possibly be causing this behaviour? You could use a free plugin called Health Check and Troubleshooting to carry out such testing.
When in Troubleshooting mode all plugins will be deactivated and only the admin of the site carrying out the troubleshooting would see those changes. Any customers visiting the site would see no changes at all.
Once you have disabled all other plugins and switched themes if the behaviour is resolved you can then enable your theme and site plugins testing after each one is enabled until the behaviour returns to locate the culprit.
https://docs.woocommerce.com/document/how-to-test-for-conflicts/