Red Rotary Phone
It’s a pretty tall building, isn’t it? And aerodynamic.
If you go down deep enough, to the fundaments, you will find the rocket fuel, and under that you will find the thrusters. The metal canisters have been there since the 50’s, so there is no guarantee that anything will work, but it’s there. If you pound them you can hear it sloshing. Cobwebs galore, all over, and the displays are stuck, in all likelihood. Search enough and you will find the manual with all the telephone numbers and launch codes.
There is a red rotary phone on a rickety table.