GitHub - G6EJD/ESP32_RTC_RAM: How to use the ESP32 RTC RAM
The ESP32 module, a close look at the brain of your dev kit
222 More Memory for the ESP32 without Soldering (How-to adapt partition sizes) - YouTube
ESP32 Flash Memory - Save Permanent Data | Random Nerd Tutorials
ESP32 - Out of memory - How to solve this compiler error and get more of the memory you paid for! - YouTube
Use PSRAM
ESP-32S Development Board WiFi Bluetooth - RAM Electronics
How to use 4Mb external PSRAM on ESP32 WROVER module.? - ESP32 Forum
ESP32 Wrover DevKit Board with 4MB RAM, compatible with Arduino IDE (WiFi Module & Bluetooth, successor to the NodeMCU ESP8266) with Pinout and Tutorials in English : Amazon.nl: Electronics & Photo