An SRT file, also known as a SubRip (.srt) file, is one of the most frequently used raw closed caption or subtitle file formats. Typically, a raw file such as an SRT or another form of supported "closed caption file" is generated during the post-production phase of a podcast. The raw caption file can be submitted as a separate file when you publish a podcast episode in your Podbean.com account.  Podbean will host the .srt file alongside the podcast episode file. The closed caption(subtitle) is supported in the podcast website, embedded players, and the Podbean pro app.). 

To generate a .srt file,  you may use SubRip or an online service, such as  Rev.com.  You can check out this link from REV.com on how to create an SRT file.  Select the “SubRip .srt” as your output file format to make it compatible with Podbean Apps and players. 

The difference between Subtitles and Transcripts

An SRT file is a subtitle file that will allow your words to show up at specific timestamps on a timeline. A typical SRT file will be formatted as in the photo below: 

(source: Wikipedia)

A transcript is simply the text of your podcast without timestamps.