Is the commission imposed for cashing out funds received via e-wallets, or the commission paid to a merchant for sending an amount to the wallet with a three-day delay in repayment, considered usury (riba)?

It is permissible for the merchant to take a commission on converting cash in the wallet, as this commission is considered a fee (ujra) and not usury (riba). However, it is not permissible to delay payment for three days while also taking a commission, because this would be considered a loan, and every loan that brings a benefit to the lender is usury.