Adding alt tags on close and check boxes?

[NCastro]

Hi,
Our website is for blind individuals who mainly use screenreaders to access the internet. The X to close chats in chatrooms or in private chats isn't navigable via keyboard. Also the checkboxes under chat settings to tell if something is checked or unchecked also doesn't show up for screen reader users. Does anyone know of any way to add an alt tag or some type of text label to either to see if that fixes the issue? Thanks