How can I roam my Mtn no 08035317455 in the US

Roaming my mtn line with Benin

I forgot to activate my MTN line before I traveled out of South Africa. I have enough airtime, thus the roaming cost is not the problem. Basically, my sim card is just showing...

I am already abroad and forget to activate roaming while in Zambia. Please I need help to get connected.

How can I roam my mtn line here in uk