ClientAuth certificates are being deprecated 

Got this error trying to issue a new certificate:

{“type”:”urn:ietf:params:acme:error:badCSR”,”detail”:”ClientAuth certificates are being deprecated by Q2 2026, please see https://pki.goog/updates/may2025-clientauth.html for the phased rollout schedule. Requests for clientAuth certificates must set the `?client_auth=true` query parameter in the ACME directory URL.”,”requestID”:”pn1B3IfzwR8Di0WuFK2UVg”}

FIX:

Upgrade asme.sh to the latest dev version:

acme.sh  --upgrade -b dev

Encrypt WordPress Server with Let’s Encrypt SSL certificate

# Install acme.sh tool
git clone https://github.com/Neilpang/acme.sh.git

cd acme.sh

./acme.sh --install

#install cert
cd ~/.acme.sh
# issue a RSA cert
sudo ./acme.sh --issue --d blog.zhenglei.net -w /var/www/html/wordpress

# issue a ECC cert
./acme.sh --issue -d blog.zhenglei.net -w /var/www/html/wordpress --keylength ec-256

# Copy the cert into target directory
sudo mkdir -p /etc/nginx/ssl

sudo ./acme.sh --installcert -d blog.zhenglei.net --key-file /etc/nginx/ssl/blog.zhenglei.net.ecc.key --fullchain-file /etc/nginx/ssl/blog.zhenglei.net.ecc.bundle --ecc
sudo ./acme.sh --installcert -d blog.zhenglei.net --key-file /etc/nginx/ssl/blog.zhenglei.net.key --fullchain-file /etc/nginx/ssl/blog.zhenglei.net.bundle
# Update nginx config
server { #listen 80; listen 443; ssl on; ssl_certificate ssl/blog.zhenglei.net.bundle; ssl_certificate_key ssl/blog.zhenglei.net.key; ssl_session_timeout 5m; ssl_protocols SSLv3 TLSv1; ssl_ciphers ALL:!ADH:!EXPORT56:RC4+RSA:+HIGH:+MEDIUM:+LOW:+SSLv3:+EXP; ssl_prefer_server_ciphers on; ... }
server {
listen 80 default_server; server_name blog.zhenglei.net;

# Let's Encrypt, http method
location ~ \.well-known
{
root /var/www/html/wordpress/;
allow all;
access_log on;
log_not_found on;
} return 301 https://$server_name$request_uri; }