thanks,Jovan.
The link you give is the one I use.

After log in,there is button to edit detail and modify flight,
but not for add baggage.
I have try in PC labtop Ipad and smartphone,
No button for add baggage at all.
Could it be the reason of buying flight with travel agent ,
not direct by airline?

I am serious.I have no status at all.
Prepay/airport is 20/35 euro,
which is silly to pay more,if it's problem about website .

Any advice is apprreciated