File indexing and searching is disabled

Hello,

I installed filerun on my vps and copied my files into the data folder.
I can see my files in the Web UI so everything is good so far.

I know that files created outside FileRun should be indexed to be shown in the search panel.

When I try to run reindex_files.php I get an error saying : "File indexing and searching is disabled"

I just wanna be able to search files by their name, searching by their content doesn't interest me.

So what should I do to be able to run reindex_files.php ? 

Thank you for your help