Try the steps below to see if this can help you with your request
For exporting text message on Android devices there is a helpful program called SMS Backup+ that is a great tool to accomplish this task. The software works in conjunction with any Gmail email account to let users backup, save, and print their text messages.
Detailed Steps to save text messages - Android
Make sure you have a Gmail email account.
Open Gmail and enable IMAP.
Install and launch SMS Backup+.
Choose "connect" and allow access to your contacts.
Accept the send and view permissions for SMS prompt.
With your Gmail account connected choose "Backup" in SMS Backup+.
When the backup completes you will now have copies of your important text messages saved forever!
Print the text messages and download them offline for safekeeping.