How do I upload a file to an FTP server using a batch script?

You have to put the ftp commands to a separate file. You cannot put lines you otherwise type on terminal to .bat file and expect it to behave identically. The .bat file can include only Windows commands. When you run the ftp command from the batch file, it waits for its commands. It does not know about the .bat file, so it cannot read the commands from there.

So put your commands to a separate text file (e.g. ftp.txt).

open 142.245.30.165 21
TESTA9MS
test11
binary
put E\PGP\test_pg
quit

And run it from the .bat file like:

ftp -s:ftp.txt
pause

If you really need to use a dynamic file name (from an environment variable), you need to create the text file on-the-fly. The ftp does not support variables.

If you use a better FTP client, you might be able to both have the commands in the batch file and use the environment variables.

For example with WinSCP:

set MyPath=E\PGP\test_pg

winscp.com /command ^
    "open ftp://TESTA9MS:[email protected]" ^
    "put ""%MyPath%""" ^
    "exit"

pause

For an introduction to scripting with WinSCP see:
https://winscp.net/eng/docs/guide_automation

There's also a guide to Converting Windows FTP script to WinSCP script.

(I'm the author of WinSCP)