Indirect Formula Issue

[Howardc1001]

I have a workbook called profit2021.xls


I am trying to combine the indirect function to refer to the value on sheet which I have listed in E1

I get a message there is a problem with this formula


It would be appreciated if someone could kindly amend my formula

 ="[profit2021.xls"&indirect("'"&e1"'"&"!"&"$C$520")

[mehmetcik]

=INDIRECT("[profit2021.xlsx]"&E1&"!"&"$C$520")

[Howardc1001]

Thanks for the help. Formula works perfectly