Modify product price based on price with tax included

I'm building a Woocommerce store and I need to get all the prices with tax included to end in zero (For example, if the original price with tax included is 1234, then I round it to 1240).

Products are imported to my website in bulk (+2800 products) but they have the price without tax. I configured the tax in woocommerce settings and I display prices with tax included in the store.

To fix the "ending in 0" problem, I created a method to change the tax value so the final price ends in 0:

// Calculate tax
function filter_woocommerce_calc_tax( $taxes, $price, $rates, $price_includes_tax, $suppress_rounding ) { 
    $key = array_search('IVA', array_column_keys($rates, 'label')); // find tax with label "IVA"
    $tax = $taxes[$key]; // get the current tax
    $subtotal = $price + $tax; // get the total
    $final = ceil($subtotal / 10) * 10; // modify the total so it ends in 0
    $new_tax = $final - $price; // calculate new tax price
    $taxes[$key] = $new_tax; // update tax in array
    return $taxes; // return new calculated taxes
};
add_filter( 'woocommerce_calc_tax', 'filter_woocommerce_calc_tax', 10, 5 ); 

It works really good, but I figured that if I change the tax price, I'm actually changing the tax rate (%) and I can't do that for legal reasons.

That's why I wanted to change the price of the product without tax instead.

I can use the same method:

$final = ceil($subtotal / 10) * 10; // modify the total so it ends in 0
$new_price = $final - $tax; // new price without tax

But I don't know what hook to use to achieve this.

Is is possible to change the price with hooks and filters?

source https://stackoverflow.com/questions/71414341/modify-product-price-based-on-price-with-tax-included