How can use fnd_request.submit_request in hook IBY_FD_EXTRACT_EXT_PUB- Urgent

Hi Gurus,

I have custom logic to generate the extended tag in hook IBY_FD_EXTRACT_EXT_PUB. It's working fine, now I have requirement to submit a custom conc. program after xml tag generation, I tried calling fnd_request.submit_request from package IBY_FD_EXTRACT_EXT_PUB, but it's not working, even it's not returning extended tag. Please help here.

Thanks,

Shishir