Isolation forest - grouped by
Here is solution if somebody will need it someday

def groupreg(df):
    a=df[['EUR']].values
    # train isolation forest
    model = IsolationForest()
    model.fit(a)
    return pd.Series(model.predict(a))

result=df.groupby('id').apply(groupreg)
#print(result)

#print(isolationforest(data2))
df['outlier1'] = result.tolist()
print(df)