Troubleshooting icon display issues on buttons

The community member is having an issue with adding icons to buttons on their website. When they use the is-icon combo class, no icon appears. When they try to paste an icon directly into the button, it appears beside the button instead of within it. Other community members suggest that the is-icon class is only for positioning and that the community member would need to manually add an icon from a style guide or icon library and then use the is-icon class to position it correctly. One community member also suggests that the issue may be because the button is actually a link block element rather than a button element, and that nesting elements within a button requires using a link block.