Please help us help you and fill where relevant:
Your LimeSurvey version: [6.5.4]
Own server or LimeSurvey hosting: Lime Hosting
Survey theme/template:
==================
(Write here your question/remark)

I want to send the respondent from Lime survey to another platform to complete the survey and bring him back once they screen out or complete the survey. please guide me.

I don't think you can bring people back to the survey. You can send then to a different platform, but I don't think you can bring them back to the last position in Limesurvey.

What you can do is use 2 Limesurvey surveys. The first survey sends them to the external survey and then the external survey sends them to the second limesurvey survey.

I think You can just use the End URL for this.
www.limesurvey.org/manual/URL_fields#End_URL_field

If you have different link : maybe you can use Start Url to prefill a question and with this one : know the end url to use.
www.limesurvey.org/manual/URL_fields#Start_URL
 

Maybe place the other survey in an iframe and use JavaScript messages to communicate between the two sites.

- developer.mozilla.org/en-US/docs/Web/API/Window/postMessage

I don't think it's LimeSurvey to LimeSurvey system here.

It's "website" to LimeSurvey to "website"

@quantifyai : please more detail , please see stackoverflow.com/help/how-to-ask

I want to send the respondent from Lime survey to another platform to complete the survey and bring him back

Sounds pretty clear to me:

1. Start in Limesurvey
2. Send respondent to another platform
3. Get respondent back (into Limesurvey I assume)

Then with SESSION : it must not break ? It work out of the box (maybe ?)