How to set up Reference in ToDo

Hi folks!

In ToDo, there are Reference. But to fill that lines possible for System Manager only.
We need to have possibility for all roles to use this Reference … Where and what we have to change to give the permission to system users, not only system manager?

DocType ToDo for all is the same - it don’t work

Reference is automatically set when you assign any document to any user. You don’t need permission for that.