If you see an error message like the following one on your microcontroller (such as ESP32):
E (46462) esp-tls-mbedtls: mbedtls_ssl_handshake returned -0x0010
this means MBEDTLS_ERR_MPI_ALLOC_FAILED. In other words, mbedtls can’t allocate enough memory for its operation.
In order to fix this, try to reduce the amount of memory other parts of your application consume.