How to copy lyric to songs that has no lyric

How to copy song lyric to Roon Core? I am using StOM server.

Roon obtains lyrics from its metadata partners at the moment and you cannot import lyrics into Roon yourself. However, Roon is actively considering providing this facility and are seeking feedback in this thread…

I copy the track lyrics (per album) in a PDF-file, which I then put in the album folder.
This PDF is visible/accessible in Roon, opening a 2nd app reading the PDF.