Script
.product-form__buttons .shopify-payment-button,
.shopify-payment-button__button--unbranded,
.shopify-payment-button__button--unbranded:after {
border-radius: 30px;
}
Esse tutorial foi util?
.product-form__buttons .shopify-payment-button,
.shopify-payment-button__button--unbranded,
.shopify-payment-button__button--unbranded:after {
border-radius: 30px;
}