You need subtitles in SBV — the compact format YouTube once used for caption uploads. It is deceptively simple: a single line holding the start,end pair (with periods, not commas), the text underneath, and a blank line before the next entry. No cue numbers, no arrows.
The SRT to SBV Converter reshapes your timed SRT into exactly that shape. It rewrites each timestamp from HH:MM:SS,mmm to H:MM:SS.mmm, joins the pair with a comma on one line, keeps your multi-line text, drops the SRT numbering, and separates entries with blank lines. The result is ready for any SBV-consuming tool.