Hi there!
Are you using the edulif template with sp lms?
If yes, here is sample code for you need to put on your custom CSS to get rid of that button:
.com-splms.view-course .course-details .splms-course-banner-right .splms-course-buy-button-wrapper .btn.btn-primary
{
display: none;
}
Note: Path towards custom CSS:
Extensions>Templates>Styles>
Click on your current default template name then choose Template Options.
Then find custom CSS within the custom code.
https://prnt.sc/pu705g
https://prnt.sc/pu70zn
Best Regards