How To Convert Txt To Srt: File

At 0:01 This is the first line of subtitles.

1 00:00:01,500 --> 00:00:04,200 This is the first line of subtitles. how to convert txt to srt file

1 00:00:01,000 --> 00:00:04,000 This is the first line of subtitles. At 0:01 This is the first line of subtitles

2 00:00:05,000 --> 00:00:07,500 This is the second line, continued here. 500 This is the second line