@Heidi-Hansen here is a script to export subtitles to SRT file made by @jetdv

using System;
using System.Collections.Generic;
using System.Collections;
using System.IO;
using System.Text;
using System.Windows.Forms;
using System.Globalization;
using System.Drawing;
using System.Runtime;
using System.Xml;
using ScriptPortal.Vegas;

namespace Test_Script
{
    public class Class1
    {
        public Vegas myVegas;
        public static FileStream OutStream;
        public static StreamWriter OutWriter;

        public void Main(Vegas vegas)
        {
            myVegas = vegas;

            int Counter = 1;

            SaveFileDialog ofd = new SaveFileDialog();
            ofd.Filter = "SRT File (*.srt)|*.srt|All Files (*.*)|*.*";
            ofd.Title = "SRT File Location & Name";
            DialogResult dr = ofd.ShowDialog();
            if (dr == System.Windows.Forms.DialogResult.OK)
            {
                string filename = ofd.FileName;

                OutStream = new FileStream(filename, FileMode.OpenOrCreate);
                OutWriter = new StreamWriter(OutStream);

                RulerFormat saveFormat = myVegas.Project.Ruler.Format;
                myVegas.Project.Ruler.Format = RulerFormat.Time;

                foreach (Track myTrack in myVegas.Project.Tracks)
                {
                    if (myTrack.IsVideo())
                    {
                        foreach (TrackEvent evnt in myTrack.Events)
                        {
                            if (evnt.Selected && evnt.ActiveTake.Media.IsGenerated())
                            {
                                VideoEvent vevnt = (VideoEvent)evnt;
                                Effect gEffect = vevnt.ActiveTake.Media.Generator;

                                if (gEffect.PlugIn.UniqueID == "{Svfx:com.vegascreativesoftware:titlesandtext}")
                                {
                                    OFXEffect ofx = gEffect.OFXEffect;
                                    OFXStringParameter tparm = (OFXStringParameter)ofx.FindParameterByName("Text");

                                    RichTextBox rtfText = new RichTextBox();
                                    rtfText.Rtf = tparm.Value;
                                    string SubTitle = rtfText.Text;

                                    string startTime = evnt.Start.ToString().Replace('.', ',');
                                    string endTime = evnt.End.ToString().Replace('.', ',');
                                    string times = startTime.Trim() + " --> " + endTime.Trim();

                                    OutWriter.WriteLine(Counter.ToString().Trim());
                                    OutWriter.WriteLine(times);
                                    OutWriter.WriteLine(SubTitle);
                                    OutWriter.WriteLine(""); //blank line

                                    Counter++;
                                }
                            }
                        }
                    }
                }
                myVegas.Project.Ruler.Format = saveFormat;

                OutWriter.Close();
                OutStream.Close();
            }
        }
    }
}

public class EntryPoint
{
    public void FromVegas(Vegas vegas, string scriptFile, XmlDocument scriptSettings, ScriptArgs args)
    {
        Test_Script.Class1 test = new Test_Script.Class1();
        test.Main(vegas);
    }
}

Just select all text events and run the script, then it will save to an srt file.