Interaction term in Unconditional Quantile regression

[Anuradha Saikia]

Dear all.
How do I incorporate an interaction between a continuous and a dummy variable in my unconditional quantile regression model?
My model has N=178 and T=14.
Also DT: disputed taxes
and InsD: dummy variable showing institutional distance
are my variables to be used in interaction.
Please find the code for the base quantile regression

xtrifreg ROA DTTA LEV Age Size GDPpercapita , fe i(Companynum) q(90) bootstrap    reps(200)
Bootstrap xtrifreg (200)

[Anuradha Saikia]

I tried using the xtrifreg command. but this is what I got.

 xtrifreg ROA c.DTTA##i.InsD LEV Age Size GDPpercapita , fe i(Companynum) q(75) bootstrap reps(200)
factor-variable and time-series operators not allowed
r(101);