Unable to crosslink a document [ ] to a reference

I’m trying to crosslink a document [number] to a reference at the end of the document. I also need to remove the grey box and replace it with a “hyperlink” from the [number] that takes you to the that reference. I tried but it doesn’t seem to work.

Please edit your question to describe your procedure: are you using Insert>Cross-reference to reference a bookmark? Are you using a bibliography? Are you using endnotes? Any other feature?