Can I apply H1b from different employer even though I am having H1 from current employer


I am holding H1 visa from current employer A (stamping is not done yet) but current employer is not sending me as no projects. Can I apply another H1 from different employer B without informing them that I am already having H1 from current organization?

Please note I dont have receipt number or any other information, only email confirmation I received from out mobility team that its picked in lottery and RFE is also approved by USCIC.