My nginx include for TLS A+ rating at ssllabs.com/ssltest using freenginx/1.31.1

TLS

# version 2026 may 23
ssl_certificate /etc/letsencrypt/live/my.domain.net/fullchain.pem;
ssl_certificate_key /etc/letsencrypt/live/my.domain.net/privkey.pem;
ssl_trusted_certificate /etc/letsencrypt/live/my.domain.net/chain.pem;

ssl_protocols TLSv1.2 TLSv1.3;
ssl_ciphers ECDHE-ECDSA-AES128-GCM-SHA256:ECDHE-RSA-AES128-GCM-SHA256:ECDHE-ECDSA-AES256-GCM-SHA384:ECDHE-RSA-AES256-GCM-SHA384:ECDHE-ECDSA-CHACHA20-POLY1305:ECDHE-RSA-CHACHA20-POLY1305:DHE-RSA-AES128-GCM-SHA256:DHE-RSA-AES256-GCM-SHA384;
ssl_prefer_server_ciphers off;

# Regenerate without -dsaparam: openssl dhparam -out /etc/ssl/dh4096.pem 4096
ssl_dhparam /etc/ssl/dh4096.pem;
ssl_ecdh_curve secp384r1;

ssl_session_cache shared:MozSSL:18m;
ssl_session_timeout 1d;
ssl_session_tickets off;

resolver 1.1.1.1 1.0.0.1 [2606:4700:4700::1111] [2606:4700:4700::1001] valid=2h;
resolver_timeout 9s;

# OCSP stapling is phased out by LE..
#ssl_stapling on;
#ssl_stapling_verify on;

add_header Strict-Transport-Security "max-age=31536000; includeSubDomains; preload" always;

# HTTP/3 — single consolidated Alt-Svc header
add_header Alt-Svc 'h3=":443"; ma=86400';

don't use
add_header Content-Security-Policy "default-src 'self' 'unsafe-inline' 'unsafe-eval'; img-src 'self' data:;" always;
it ruins all iframes and/or embedded remote media.