HEllo @Lee Frank !
Welcome to Microsoft QnA!
Azure TTS does not directly support SRT files as input sources. However, you can convert the text content of the SRT file to a supported format, such as plain text or SSML (Speech Synthesis Markup Language), and then use that as the input for the TTS service. You can also use a third-party tool to convert the SRT file to a compatible format before passing it to the TTS service.
Kindly mark the answer as Accepted and Upvote in case it helped or post your feedback to help !
Regards