Array join with in that need array sort

I have a dataframe like this:

   usr     sec    scrpt
0  1        5     This
1  2        10      is
2  3        12       a
3  1        7    string
4  2        4      oreo

I am trying to order/sort by user,sec and then group by on user and concat the string there. So this table consist of every user call there in which second what did he speak . so resulting dataframe should look like

user   concated
1      this string
2      oreo is
3      a

I have tried

Array_join(array_sort(collet_set(script)),'|')as new