You should use Write Cell Instead of Assign Activity as below :-
I am attaching the workflow for the same :-
MainPratik.xaml (7.5 KB)
Note :- Within WriteCell Activity in the Range property instead of “A” use the Alphabet Letter of the column in which you want to write the Values
Mark as solution and like it if this helps you
Happy Automation
Best Regards
Er Pratik Wavhal