This is my first time trying to pay my Unifi with M2P Amex, I search MAE and found "TM Tech (Telekom Malaysia) - Bill payment"

Is that the correct one for Unifi payment?

Yes. Choose AmEx and pay on weekend.

Scan & Pay -> PAY -> Change -> CARDS -> [Amex] -> Proceed

Please note
No weekend CB or Treat points for QR Pay transactions.
No token to play Tap & Win.
Not many merchants will accept if the source of fund is by credit card. (Normally the merchants have card device accept Amex so swipe Amex card that give Cashback/Treat points)

Not difficult with Spaylater.
But it won't last long, enjoy it while it lasts.

Also can buy groceries, petrol, dining at Lazada App and Shopee App. Both accept Amex.

Wanna ask, i accidently paid wrong MBB card, can MBB CS helps to transfer the payment to the other cards?

Well, contrary to what you said, i manage to get it done.
Yes.
Yeap, got it done this morning. 
I got it done via MBB online chat CS this morning, just that need to wait for 5 days and not to use the wrongly paid card.
he didnt mention anything as goodwill nor one time only. Pretty easy to submit the request.