I was panicked and when I saw that Hitler brought three other Nazi generals I had little to say. I agreed with all of Hitler's terms.
I told Schuschnigg that he was to lift any restrictions the Nazi party in Austria and to release Nazis from prison. I demanded him to sign the agreement and make the changes within three days or I would invade.
1938
However, I still had a plan as I knew what Hitler wanted! He was claiming that the people of Austria agreed with the Anschluss. So I decided to hold a plebiscite to see what the public really thought. If they voted against the Anschluss Hitler would have no reason to invade.
March - April, 1938
On the 12th of March we invaded Austria. Unfortunately, I planned it badly as our tanks need to stop at Austrian petrol stations to refill. Commanders used tourist guides to find their way to the capital. Not a single drop of blood was shed. People even cheered for the troops when they entered towns and offered them gifts!
On the 10th of April I held a plebiscite that I had discussed with Seyss-Inquart (chancellor). There was a heavy presence from Nazi 'stormtroopers' and unsurprisingly 99% of Austrians voted in favour of the Anschluss.