TCU pairing requires no button presses.

The TCU goes into pairing mode for the first few minutes after ign is switched on.

So:
Put your phone into BT search mode
Then turn on vehicle ign
See what happens

I have head from some people that an eject box may need to be fitted to allow the TCU to go into pairing mode, although this is unconfirmed.

However, no button presses are required for pairing mode.