NA's for PVWatt's API

Question

Using PVWatt's API tool, I am trying to create a code in R that will read a list of rows (located within dataset "test.csv") each containing a specific latitude and longitude coordinate. I would like for the code to return annual kWh values for each row. I tried with the following code but the new columns "AnnualEnergy" and "CapacityFactor" contain NA values:

library(httr)
library(jsonlite)

# Read data from CSV file
data <- read.csv("test.csv")

# Function to send request to PVWatts API for a single location
pvwatts_request <- function(latitude, longitude) {
  url <- "https://developer.nrel.gov/api/pvwatts/v8.json"
  parameters <- list(
    api_key = "XXX",
    lat = Latitude,
    lon = Longitude,
    system_capacity = 4, # Example system capacity (kW)
    module_type = 0,    # 0: Standard, 1: Premium, 2: Thin film
    losses = 14,        # System losses (percent)
    azimuth = 180,      # Azimuth angle (degrees)
    tilt = 20,          # Tilt angle (degrees)
    array_type = 1,     # 0: Fixed, 1: Tracking
    module_parameters = toJSON(list(
      "module_efficiency" = 0.16  # Example module efficiency
    ))
  )
  response <- GET(url, query = parameters)
  content(response, "parsed")
}

# Create empty columns for PVWatts API results
data$AnnualEnergy <- NA
data$CapacityFactor <- NA
# Add more columns as needed

# Iterate over rows, send requests, and store results
for (i in 1:nrow(data)) {
  latitude <- data[i, "Latitude"]
  longitude <- data[i, "Longitude"]
  result <- tryCatch(pvwatts_request(latitude, longitude), error = function(e) NULL)
  
  if (!is.null(result) && !is.null(result$outputs)) {
    data[i, "AnnualEnergy"] <- result$outputs$ac_annual
    data[i, "CapacityFactor"] <- result$outputs$capacity_factor
    # Add more columns as needed
  } else {
    cat("Error occurred or empty response for row", i, "\n")
    cat("Latitude:", latitude, "Longitude:", longitude, "\n")
    print(result)  # Print out the API response for inspection
  }
}

# Save updated data to a new CSV file
write.csv(data, "data_with_results2.csv", row.names = FALSE)

I asked ChatGTP 3.5 to develop the code, and that is what it came up with. I was expecting to return annual kWh values for each entry.