It's a HuaweiB525 which according to the specs yes.
Socket for external antenna: 2 x SMA
This might interest you - https://ausdroid.net/2019/01/20/optus-4g-wireless-broadband-steroids-can-triple-wireless-broadband-p...
Thanks for that.
This is a step to far for what I plan to do. I am getting a small plugin antenna for when I am on the train as the reception is spotty and a co-worker who added an antenna that he kept in the outer pocket of his bag resolved this issue on the almost identical commute.
Can you please describe what you need help with in a bit more detail?
What are you wanting to connect?
Have you already contacted Optus? What was the outcome?