hello and good day to all,
I am using the local projection method for my thesis, (panel data ) , I do not know how can I add the country-specific time trends as control, in terms of the robustness check of my estimation. my adviser told me to do some robustness check like this . I hope I receive your advice,

my baseline estimation is as follow:

Code:
local hmax = 5
forv h = 0/`hmax' {

asdoc reghdfe lnfertility`h' l(0/2)dummy_hini l(1/2)lnfertility , absorb( i.ifscode i.year) vce(cluster ifscode)
many thanks for your valuable time and advice.

best regards ,