433MHz 4-button code copy

[bsdinis1]

I've reverse engineered a cheap 433MHz remote with 4 buttons and code copy. I'm trying to understand how it works so that I can interface it with my own microcontroller. I'd very very grateful if anyone can explain how this works and how can I interface this circuit with my own ESP32.

The red rectangle is the FT60E021 microcontroller with all of its pins labeled. Q1 and Q3 are 2SC3356-R25 Silicon Epitaxial Planar Transistors (marking R25). Q4 is an S8050 general purpose NPN transistor (marking J3Y). Q5 is an MMBTH10L general purpose NPN silicon transistor (marking 3EM). Q6 is an S8550 general purpose PNP transistor (marking 2TY). X1 is an SR1 433.92MHz SAW resonator (marking B01).