CURL_SSLVERSION_TLSv1_3

CURL_SSLVERSION_TLSv1_3 is one of the accepted parameters for curl_setopt parameter #3 (optionally as a bitmask).

CURL_SSLVERSION_TLSv1_3 — Available as of PHP 7.3.0 and cURL 7.52.0

CURL_SSLVERSION_TLSv1_3 = 7;