After a struggle I have learned how to adapt my keyboard to Old Norse characters. In Windows I used the 'Insert' icon, then went to 'Symbols, selected the appropriate characters and so on and it worked. For example  I have designated  the control key and the 'o' and 'a' keys to produce 'o-umlaut'.  But when I try the same procedure online, nothing happens. Can anyone help me? I would be grateful.
Cheers,
 Jed