Encouraging ‘mama’ help!

Hi my little boy didn’t say much at all until he turned 18 months now he’s got around 15-20 words all very random tree cheese keys 😂.

He will not say mam/mama he used to imitate it then said it once or twice, but not once has he said Mam/mama since the end of last year he’ll say dada granda and even one of his cousins names but not me it’s sad I would love to hear him shout of me even though I’m sure after a while I’ll change my mind 😂

Anyone suggest anything?