does not compile：MEM_LOWER_LIM

[sgstudio2024]

F:\Users\Administrator\Desktop1\ESP32Marauder-master\esp32_marauder\WiFiScan.cpp: In member function 'bool WiFiScan::checkMem()':
WiFiScan.cpp:381:35: error: 'MEM_LOWER_LIM' was not declared in this scope
381 | if (esp_get_free_heap_size() <= MEM_LOWER_LIM)
| ^~~~~~~~~~~~~
exit status 1
'MEM_LOWER_LIM' was not declared in this scope