Missed a kaddish at maariv

Hi,

In the maariv evening service, the chazan is supposed to recite a half-kaddish before beginning the amidah. However, this half-kaddish is not a firm requirement. Therefore, if the chazan forgets the half-kaddish and begins the amidah, there is no corrective; the service proceeds from there.

(Rivivot Ephraim 1:175:1)

Have a great day,
Mordechai