how to change default button in squarespace to a custom png file?

Site URL: https://www.wallerei.de/

.sqs-block-button-element--large.sqs-block-button-element {
background: url('https://static1.squarespace.com/static/62df123eb6a96635d077a277/t/63036657eb9c76699f749084/1661167191901/6.png');
color:#ffff;
text-align: center;
border: none;
height: 40px;
width: 40px;

I applied this code but it didn't work out. Can you help please?

Can you share link to page where you use button? We can help easier