Good news for anyone who needs to change their address or has lost (or had stolen) their WA residence permit.
The online étrangers administration portal has finally been updated so that you can create an account using the number on your WA card. The link to the page is here
You will be asked to create an account: to do so, you need to use your numéro personnel which you’ll find it on the front of your card just above your signature, NOT the alphanumeric number at the top right OR the six figures in bold in the bottom right corner. You need to create a password and verify your account via an email link