Can only export .srt captions

When I try to export a closed captions file from PP, the only option is .srt. This applies whether I go through File-->Export--> Captions or, from the export panel, when I choose the sidecar option, there is no way to change the output format from .srt. Is there a file I have to download or something that will enable other formats, specifically .scc?

Using PP 23.4.0