Here’s a quick question? Can we use axis y Niacinamide spot serum and ordinary azeliac acid in different routines but same day?

Yea, I think it's okay.

Yes no problem

Sure I don't see there being a problem. If it irritates your skin, spread them out farther.

using both niacinamide and azelaic acid is good, so it's not a problem

Usually even for sensitive skin, you can use niacinamide + azelaic acid right after one another in the same routine! But if you’re worried about the effects/just trying out the combo, you can put on a barrier cream (I put one in this comment that I love for my sensitive skin) after applying both or incorporate one in ur AM routine and the other in your PM routine.