HI @Janelle_Tan
In this case you need to create Type into activity for all the field that you need to enter
If you Assign it as Array of String like this New String(){"Qty1","Qty3","Qty3"}
Like this below you need to add all the value in the Type into activity
Qty1(0)
Qty2(1)
Qty3(2)
Regards
Gokul