does smelling something invalidate tha fast of Ramadan ( because on 2nd Ramadan i was sleeping an have a wet dream ejaculate during deep sleep i thought my fast become void I smelled something and later came to know that ejaculation in deep sleep does not invalidate the fast ) but my friends say that since I smelled something that invalidate my fast and if so should I give qaza only or kffara will be in order to please help me fisabilillah may

Walaikumussalam
Smelling something does not invalidate the fast
Fast is valid and in order.
Only smelling of herb are makrooh nor Haram still it will not invalidate the fast just reduce the sawab
While you were sleeping in the day time if in dream something happened and you became najis just you were needed to do the ghusl your roza was correct
Do the qadha of that roza which you have broken just because of the ignorance.
For the future I request try to contact any local alim or refer tauzeehul masayel to avoid such type of the things.
Wassalam
Syed Abul Qasim Rizvi