Azides and maleimides can react: Macromolecular Research, Vol. 24, No. 9, pp 793-799 (2016)
They sell kits for creating azido PEG3 maleimide - it has to be prepared fresh as it only survives for hours after preparation - probably from reaction of azide and maleimide.
I would very closely monitor the reaction and see if it forms and decomposes quickly. You might also want to change the linker - for some reason 2 carbon linkers tend to give poor yields in a lot of these reactions.