Error with Anomaly Detection in Time Series, using R: "Invalid input: time_trans works with objects of class POSIXct only"

Question

I am trying to run an R code to detect anomalies in time series. However, once I run this code:

#Loading the libraries
library(devtools)
library(Rcpp)
library(wikipediatrend)
library(AnomalyDetection)

# Download wikipedia webpage "fifa"
fifa_data_wikipedia = wp_trend("fifa", from="2013-03-18", lang = "en")
fifa_data_wikipedia$date <- as.POSIXct(fifa_data_wikipedia$date)
#First_look
fifa_data_wikipedia

# Plotting data
library(ggplot2)
ggplot(fifa_data_wikipedia, aes(x=date, y=views, color=views)) + geom_line()

# Keep only date & page views and discard all other variables
columns_to_keep=c('date','views')
fifa_data_wikipedia=fifa_data_wikipedia[,columns_to_keep]

#Apply anomaly detection and plot the results
anomalies = AnomalyDetectionTs(fifa_data_wikipedia, direction="pos", plot=TRUE)
anomalies$plot

# Look at the anomaly dates
anomalies$anoms

I get this error:

> anomalies$plot
Error: Invalid input: time_trans works with objects of class POSIXct only

How can I solve it ?

Note: I have also tried to use the solution proposed in Invalid input: time_trans works with objects of class POSIXct only, but it looks like not working... :(