HI all
My employer is not sharing the i-140 Number. They say they have filed the petition but not sharing the details. can anyone suggest what to do or is anyone in the similar situation as well?

Thanks

Ask employer again saying that you need it just for a reference. If not, you may try it here later
for your receipt or approval notice.

https://www.uscis.gov/about-us/freedom-information-and-privacy-act-foia/how-file-foia-privacy-act-request/how-file-foiapa-request

My employer also didn't provide me the receipt number but I contacted my lawyer secretly and he provided it to me. I got approved within 7 days including weekends.

You can get it by filing FOIA(Freedom of Information Act). It is simple process and can take few hours.

See sample here - https://drive.google.com/file/d/0B4CUlpEts1T-aVRpSmpCTDlaVFk/edit