Several payment buttons are displayed for Checkout

The PrestaShop Checkout module uses the "displayPaymentByBinaries" hook to replace the native "Place order" button (to learn more about hooks, see the article the hook system).

Many custom themes do not implement the CSS rules for this hook. You can fix this by adding the missing native CSS rules to your custom theme:

• Open the file /themes/THEME_NAME/assets/css/custom.css.
• Then copy and paste this at the end.

.js-payment-binary {
    display: none;
}

.js-payment-binary .accept-cgv {
    display: none;
}

.js-payment-binary.disabled {
    cursor: not-allowed;
    opacity: 0.6;
}

.js-payment-binary.disabled::before {
    position: absolute;
    top: 0;
    right: 0;
    bottom: 0;
    left: 0;
    pointer-events: none;
    content: "";
}

.js-payment-binary.disabled .accept-cgv {
    display: block;
}

Save the changes and clear the cache.

To learn more about theme customization related to the Checkout module, you can consult this page (in English): https://github.com/PrestaShopCorp/ps_checkout/wiki/PrestaShop-Checkout---theme-customization.