How to push completed ODK submission on ODK Central Server?

1. What is the problem? Be very detailed.
I would like to push the completed ODK form on ODK Central.

2. What app or server are you using and on what device and operating system? Include version numbers.
ODK Central v1.2.0

3. What you have you tried to fix the problem?
Previously, I used ODK Briefcase, however, this time ODK Briefcase is not working anymore.

4. What steps can we take to reproduce the problem?

5. Anything else we should know or have? If you have a test form or screenshots or logs, attach below.

Looking forward for your response.

Best,
@iamnarendrasingh

Briefcase should be able to push to Central: https://docs.getodk.org/briefcase-using/#push-to-central
What version of Briefcase are you using? What have you tried? What error messages did you receive or what doesn't work (in more detail)?