formula assist

Hi Dears, Could you please assist regarding the below formula as i have additional condition  =IFS(G$2<=EOMONTH($B18,-1)+1,$D18*Assum!$C$9,G$2>EOMONTH($B18,Assum!$K$9-1)+1-EOMONTH($B18,-1)+1,0,MOD(...