Tax and Additional Fees

Hi everyone, i need to ad a 5% Fee to every customers that checks out with Paypal on all my items. Talked to Wix today and send me here, maybe you guys can help.
Thank You.

Is it through Wix Stores or Paid Plans or just a payment through Wix Pay API for example.
https://www.wix.com/corvid/reference/wix-pay.html
https://support.wix.com/en/wix-stores/setting-up-tax
https://support.wix.com/en/article/adding-a-handling-fee-in-wix-stores

if it is Wix Stores or Wix Paid Plans, then you should look at their own pages.
https://support.wix.com/en/wix-stores/setting-up-your-store
https://support.wix.com/en/paid-plans/setting-up-paid-plans

You can add charges on at point of sale.
https://support.wix.com/en/article/adding-a-custom-amount-to-a-transaction-at-a-point-of-sale-in-wix-stores

Although, please note that you shouldn’t be passing on any Paypal fees to the customer.
https://www.paypal-community.com/t5/Chip-and-Pin-Card-Reader/CARD-FEES-THE-NEW-LAW/td-p/1403399

Wix store dont offer the option i need, i need an extra fee in % when you click on the paypal checkout button only. then paypal will load and all the infos of his/her shopping cart (as usual) plus my 5% Fee will apear on the invoice. i called wix to know how to do this and they told me to speak to you guys for what i need.

Did you mange to do this?. I cannot find an available option to charge a % or fixed fee depending on the payment method chosen by the customer.