You're right - the SHA1.h library isn't included by default. Let's modify the code to implement SHA1 directly without requiring external libraries:

This implementation now includes a custom SHA1 and Base64 implementation directly in the code, eliminating the need for external libraries. The WiFi Manager functionality allows the ESP32 to:

1. Create an access point with a captive portal if it can't connect to WiFi
2. Provide a web interface for configuring WiFi credentials
3. Store the credentials in SPIFFS
4. Automatically reconnect if the connection is lost
5. Fall back to AP mode if reconnection fails

To use this code:

1. Upload it to your ESP32
2. On first boot, it will create an access point named "ESP32_WebSocket" with password "12345678"
3. Connect to this network and navigate to http://192.168.4.1
4. Configure your WiFi credentials
5. The ESP32 will connect to your network and start the WebSocket server
6. Access the WebSocket interface at http://[ESP32-IP-ADDRESS]:81

Let's modify the code to use LittleFS instead of SPIFFS:

This code now uses LittleFS instead of SPIFFS for file storage. LittleFS is the recommended file system for ESP32 as SPIFFS is being deprecated. The changes include:

1. Changed the include from <SPIFFS.h> to <LittleFS.h>
2. Replaced all SPIFFS references with LittleFS throughout the code
3. Updated the initialization in setup() to use LittleFS
4. All file operations now use LittleFS instead of SPIFFS

The functionality remains the same, but now it's using the more modern and efficient file system. To use this code:

1. Make sure you have the LittleFS library installed in your Arduino IDE
2. Upload the code to your ESP32
3. The ESP32 will create an access point on first boot
4. Connect to the access point and configure your WiFi credentials
5. The ESP32 will connect to your network and start the WebSocket server