Dear Sara and Rui
I like to run from Adafruit Libary BME280 the bme280test with the AI Thinker ESP32-CAM using I2C. The check connection I run first 
The I2CScanner
#define SDA1 21   // not available on ESP32-CAM
#define SCL1 22   // not available on ESP32-CAM
#define SDA2 12 // connected to SDI of BME280
#define SCL2 14 //connected to SCK
Scanning I2C Addresses Channel 1
Scan Completed, 0 I2C Devices found.
Scanning I2C Addresses Channel 2
.. .. .. .. .. .. 76 .. .. .. .. .. .. .. .. ..
Scan Completed, 1 I2C Devices found.
If the bme280test is run with 
// default settings
status = bme.begin();
// You can also pass in a Wire library object like &Wire2
// status = bme.begin(0x76, &Wire2)
I get the message “Could not find a valid BME280 sensor…..”
// default settings
//status = bme.begin();
// You can also pass in a Wire library object like &Wire2
status = bme.begin(0x76, &Wire2)
I get the message ‘Wire2’ was not declared in this scope.
I would like to combine elements of your course “learn ESP32 with Arduino” with the ESP32-CAM.
I hope you can help me I like your explanation in your course.
Kind regards
Urs