Dear statalist, PPML with country, time fixed effect (dummy)

[KIM SUJIN]

Dear statalist,

I hope to run regress panel data using PPML method with country effect(dummy), time effect( dummy)
200import, export countries, 7 years

I have these variables,
log_value importcountry_i exportcountry_j log_distance_ij language log_rem_i log_rem_j log_gdp_i log_gdp_j

I am very beginner, so I do not know how to command for PPML with fixed dummy variables.

dependent variable is log_vlaue,

1. I want to make country , time dummy effect as fixed effect.

When I command, 'xtset year importcountry exportcounty' --> there is sign ' too many variables'

2. I hope to know command for PPML

3. I wonder why I don't need GDP variable if I use fixed dummy effect


Thank you so much statalist

Sincerely