r script error power bi object not found

I have modified my code to this:

# The following code to create a dataframe and remove duplicated rows is always executed and acts as a preamble for your script:

# dataset <- data.frame(Year, Sales revenue (£m))

# dataset <- unique(dataset)

# Paste or type your script code here:

# time series forecasting

dataset <- unique(dataset)

library(forecast)

# Assume the data starts from the first year available and increments yearly

sales_ts <- ts(dataset$`Sales revenue (£m)`, start = min(dataset$Year), frequency = 1)

# Fit an ARIMA model

fit <- auto.arima(sales_ts, seasonal = TRUE)  # If seasonality might be a factor

# Forecast the next 5 years

future <- forecast(fit, h = 5)

# Plot the historical data and forecasts

plot(future)

This the plot:

I'm not sure why there is a gap between the historical data and the forecast