I am trying to test a one-sided hypothesis after running a regression to see if the sum of two coefficients (X1 and x2) is greater than 0. My regression looks like this:

reghdfe y x1 x2 x3, noabsorb vce(robust)


I have tried this command:
test _b[x1] + _b[x2]=0
local sign_d = sign(_b[x1] + _b[x2])
display "Ho: coef _b[x1] + _b[x2] >=0 t= " invttail(r(df_r), ttail(r(df_r),`sign_d'*sqrt(r(F)))) " p-value = " 1-ttail(r(df_r),`sign_d'*sqrt(r(F)))

This displays the correct p-value for the hypothesis, but I am looking to test the STRICT inequality (H0: _b[x1] + _b[x2] >0) instead of _b[x1] + _b[x2] >=0. Is there any way to do this?