curl-w32/docs/cmdline-opts/proxy-tls13-ciphers.md

c	SPDX-License-Identifier	Long	Arg	help	Protocols	Category	Added	Multi	See-also	Example
Copyright (C) Daniel Stenberg, <daniel@haxx.se>, et al.	curl	proxy-tls13-ciphers	<ciphersuite list>	TLS 1.3 proxy cipher suites	TLS	proxy tls	7.61.0	single	tls13-ciphers curves proxy-ciphers	--proxy-tls13-ciphers TLS_AES_128_GCM_SHA256 -x proxy $URL

--proxy-tls13-ciphers

Specifies which cipher suites to use in the connection to your HTTPS proxy when it negotiates TLS 1.3. The list of ciphers suites must specify valid ciphers. Read up on TLS 1.3 cipher suite details on this URL:

https://curl.se/docs/ssl-ciphers.html

This option is currently used only when curl is built to use OpenSSL 1.1.1 or later. If you are using a different SSL backend you can try setting TLS 1.3 cipher suites by using the --proxy-ciphers option.