I assume you are referring to your hand-written signed name?
If that is so-
1. Create a signature in a pixel editor (Photoshop) by scanning, photographing, etc.
2. Delete any background behind the signature so as to have "transparent" pixels.
3. Save the signature image as a .PNG file (this is the only file type to preserve transparency for this purpose)
4. In Lightroom create an Identity Plate, using the signature.png as a GRAPHIC.
5. In the Print module you can add this Identity Plate anywhere on an image or its border.
If you use the signature to design a Watermark, it can only be placed on an image (not a border).
The PNG image in Photoshop on a transparent background-
The "Identity Plate" made from the graphic placed on an image in the Print module-
The "Identity Plate" placed on the print Border-