Hello,
Add the below code to Theme Options > Custom CSS and let me know if it suits your needs
.et-buy-now-clicked:after {
content: '';
border: 1px solid #fff;
border-left-color: #888;
width: 16px;
height: 16px;
border-radius: 50%;
display: inline-block;
position: absolute;
left: calc(50% - 8px);
top: calc(50% - 8px);
line-height: 1;
animation: rotate .3s infinite linear;
}
.et-buy-now-clicked {
--single-buy-now-button-color: transparent;
--single-buy-now-button-color-hover: transparent;
}
Regards