app.py

import streamlit as st
import numpy as np
import pandas as pd
import plotly.express as px

uploaded_file = st.file_uploader("Choose a CSV file", accept_multiple_files=False)
if uploaded_file is not None:
     # Can be used wherever a "file-like" object is accepted:
     dataframe = pd.read_csv(uploaded_file)
     st.write(dataframe)
     series = st.text_input("Write the name of the variable you want to forecast")
     dataframe['time'] = dataframe.index
     if series is not None:    
          fig = px.line(dataframe, x='time', y=series, title=f'Forecasting {series}')
          st.plotly_chart(fig)