How do I enter domiciles?

Domiciles are not the same as layovers.  You will be prompted to enter your domicile(s) when you first login and choose a tax year to work on.  After that initial login to that tax year, you will not be prompted to enter domiciles for that tax year again; however, you can change your domicile settings if you need to via the Tools & Settings page.

If you need to change your domiciles for a given tax year, first reset your layovers for that year.  If you do not, the data will likely be incorrect.