These are some helpful links:
Controlling Somfy roller shutters using an ESP32 and ESPHome | die-welt.net GitHub - Legion2/Somfy_Remote_Lib: Emulate a Somfy remote using a 433.42 MHz transmitter. GitHub - Nickduino/Somfy_Remote: An Arduino Sketch able to simulate a Somfy remote control Somfy Smoove Origin RTS Protocol | PushStack
These are some relevant issues:
Finally got it working - setting custom pins - NodeMCU ESP32 · Issue #127 · LSatan/SmartRC-CC1101-Driver-Lib Viproz/SmartRC-CC1101-Driver-Lib: This driver library can be used for many libraries that use a simple RF ASK module, with the advantages of the cc1101 module. It offers many direct setting options as in SmartRF Studio and calculates settings such as MHz directly.