An error of predict at prophet

Hi team,
Hope that you are doing great. i'm facing a challenge in predict of prophet package.
steps that i followed

m.add_regressor('sessions')
m.add_regressor('add_to_cart')
m.add_regressor('begin_checkout')
m.add_regressor('plp')
m.add_regressor('select_item')
m.add_regressor('search')
m.add_regressor('delivery_continue')

m.fit(train)

m.params

future = m.make_future_dataframe(periods=118)
future.head()


## then i added the regressors
future['sessions'] = df1_final['sessions']
future['add_to_cart'] = df1_final['add_to_cart']
future['begin_checkout'] = df1_final['begin_checkout']
future['plp'] = df1_final['plp']
future['select_item'] = df1_final['select_item']
future['search'] = df1_final['search']
future['delivery_continue'] = df1_final['delivery_continue']


forecast = m.predict(future)
forecast[['ds','yhat','yhat_lower','yhat_upper']].tail()

and this was the output i'm facing. searched a lot but with no resolution.