Delivery costs apply to the total excluding VAT with ecotax

[toniniyo]

Hello,

On my store, I apply the delivery costs of an amount of 9% of the total (tax excl.)

I would like to exclude the ecotax from the calculation of the delivery costs

 

In my example below, the Shipping is 133.23 € (9% of 1480.32).

I want to exclude ecotax (Eco Participation), so the Shipping must be : 9% of (1480.32 - 23.94) = 131.07 €

 

Example: 

 

What can i do please ?

Thanks