Calculating the Standardized Precipitation Evapotranspiration Index

[sultanduran]

When I study in R I have this error:
"Calculating the Standardized Precipitation Evapotranspiration Index (SPEI) at a time scale of 3. Using kernel type 'rectangular', with 0 shift. Fitting the data to a Gamma distribution. Using the ub-pwm parameter fitting method. Checking for missing values (NA): all the data must be complete. Using the whole time series as reference period. Input type is vector. No time information provided, assuming a monthly time series."
Please help me!!