OK, Used this code I found here on the forum and it makes it smaller, not the same size that “Add to cart” button but it works for me. Thanks
.paypal-button:not(.paypal-button-card) {
height: 39px;
width: 190px !important;
border-radius: 0;
}
.pisol_buy_now_button {
width: 190px !important;
}