Saving company files as Read Only

Hi,

We are using Account Edge NE V16.5

I was trying to save a Company File as "Read Only" today, & can't seem to find the right menu path.

I understand that this feature was available in previous versions via Setup > Preferences > Security, but I can't find it using that path on this version.

Would welcome any feedback that anyone can provide on this.

Thanks.

Cheers - Mark