Notched corners for buttons

Hi!

I'm wanting to create notched buttons like the button below.

I found one other thread about this, but I'm having trouble getting it to work correctly. 

I've had success with the below code showing correctly, but can't get the percentages right to make my desired shape:

.sqs-block-button-element  {

div {
  position: relative;
  width: 200px;
  height: 80px;
  overflow: hidden;
  background-color: #522d5b;
  clip-path: polygon(
    0 20%,
    10% 0,
    90% 0,
    100% 20%,
    100% 80%,
    90% 100%,
    10% 100%,
    0% 80%
  )
}

Thank you VERY much!

Can you share site url? We can test that code easier.

@tuanphan Thank you for asking/helping! https://tiger-scarlet-kmc6.squarespace.com

@tuanphan Thank you very much!