adf-test code snippets in r

for monthly time series dataset what should my adf test type be in r

for monthly time series dataset what should my adf test type be in r if i dont know whether my data is stationary or not in r

i want to check the stationarity of a time series data using adf. what lag to use for monthly data? in r

i want to check the stationarity of a time series data using adf. what lag to use? in r