Out of stock message

I recommend asking at https://www.ads-software.com/support/plugin/woocommerce/#new-post so the plugin’s / theme’s developers and support community can help you with this.

Try this in the customizer’s Additional CSS section:

.ast-shop-product-out-of-stock font:before {
    content: 'L?bimüüdud';
}
.ast-shop-product-out-of-stock font font {
    display: none;
}

If that doesn’t work for you, I also recommend what Steven suggests.

Apologies if the translation is odd, it was by Google translate.