Declaration of function cannot work in different board

Gas_sensor_reeedit:70: error: 'MQCalibration' was not declared in this scope

Ro = MQCalibration(MQ_PIN); //Calibrating the sensor. Please make sure the sensor is in clean air

^

C:\Users\User\Documents\Arduino\Gas_sensor_reeedit\Gas_sensor_reeedit.ino: In function 'void loop()':

Gas_sensor_reeedit:87: error: 'MQRead' was not declared in this scope

iPPM_LPG = MQGetGasPercentage(MQRead(MQ_PIN)/Ro,GAS_LPG);

^

Gas_sensor_reeedit:87: error: 'MQGetGasPercentage' was not declared in this scope

iPPM_LPG = MQGetGasPercentage(MQRead(MQ_PIN)/Ro,GAS_LPG);

^

C:\Users\User\Documents\Arduino\Gas_sensor_reeedit\Gas_sensor_reeedit.ino: In function 'long int MQGetGasPercentage(float, int)':

Gas_sensor_reeedit:190: error: 'MQGetPercentage' was not declared in this scope

return MQGetPercentage(rs_ro_ratio,LPGCurve);

^

exit status 1
'MQCalibration' was not declared in this scope

These is the error code