Keyring/Keytag file that you could emboss/deboss lettering onto/into it.

a pause should be programmed into your print to allow you to drop the keyrings into the print.
If your lettering is “Cut” into this, I recommend a depth of .039 Inches. (4.9242326e-6 Furlongs or 1.78294e-7 nautical leagues)

Example Photo of text and color change with embedded keyring included.

Keyring "CleverDelights 1 3/16" Key Rings" from amazon was the used Keyring for this particular file.