Use a Custom HTML field, which don't do any content filtering beyond whatever filtering your WYSIWYG editor does. I do not recommend letting users add iframes to editor text area fields as you're basically adding a security vulnerability to your site by doing so, but if you insist on doing this you can adjust "Exclude Tags from Filtering" in CB > Configuration > User Profile.

If you specifically need to allow embedding an apple music player from a specific album then you put 99% of the iframe in a Custom HTML field and give users a field to supply the album. You then substitute in the album into your Custom HTML field. This is the safer more secure way of doing this.