When the Android Samsung J4 + Plus is reset back to factory settings it will automatically be locked FRP Google Account and we are required to log in using a Google Account that was previously synchronized. 
If you don't remember the email or email password at all, then one way to do this is by bypassing it. To bypass FRP Google Account on Samsung Android we can use the Samsung FRP bypass tool software.
Easy way to ByPass FRP Samsung J4Plus
Connect the Android Samsung J4 Plus with the Internet via a SIM Card Data or Wifi Network. Then connect the Samsung J4 Plus with the computer then run the Easy Samsung FRP Tool 2020 V1 application.
Click Bypass FRP, and wait for the Easy Samsung FRP Tool application to detect and read the Samsung J4 Plus SM-J415F. Then the Samsung J4 Plus screen will automatically display the option to open the browser.
Open the browser then access the online tutorial sharing blog, open one of the online tutorial sharing blog posts then scroll down and find the download link FRP ByPass Tool.APK.
Download the Google Account FRP ByPass application that I have provided, for the FRP bypass method, as we usually use the finger exercise method with the help of the Google Account Manager application and Easy FRP Bypass.
After successfully adding (logging in) to a Google Account via the Easy FRP Bypass Application, Restart the Samsung J4 Plus to see the results.
Samsung J4 Plus will return to the setup page for the use of a new device, do the settings as usual. An Account notification will appear, indicating that the ByPass method was successful.
Finally, Samsung J4 Plus which was previously locked FRP Google Account can be used again
Thus the Tutorial Guide on How to Overcome a Samsung J4 Plus Android locked FRP Google Account using the finger exercise method, as long as it tries and good luck.