<form action="https://checkout.zen.com/payment" method="POST"><input name="terminalUuid" type="hidden" value="623FC166-5A4F-4166-812A-B5303B7ACE48" /><input name="merchantTransactionId" type="hidden" value="{order_id}" /><br /> <button style="  background-color: #000000;
  background: #ccc url('https://e-ksperci.pl/wp-content/uploads/2021/11/zen_mastercard_logo-2.svg') no-repeat top left;
  border-radius: 23px;
  width:140px;
  height:50px;
  font-size:15px;
  color:white" type="submit">Zapłać z Zen</button></form>
				
			

				
					<form action="https://checkout.zen.com/payment" method="POST"><input name="terminalUuid" type="hidden" value="623FC166-5A4F-4166-812A-B5303B7ACE48" /><input name="merchantTransactionId" type="hidden" value="{order_id}" /><br /> <button 
style="background:silver;
font-size:15px;
padding:8px" 
type="submit">Zapłać z Zen</button></form>