In order to configure the HTTPS certificate properly, acme.sh has been debugged again:
        acme.sh --issue -d www.v-signon.com --webroot /root/vso-www/

    nginx's www domain with HTTPS permanent redirection has been also configured:
    
    server{
        listen 443 ssl;
        listen [::]:443 ssl;
        server_name www.v-signon.com;
        ssl_certificate /root/myacme/ssl/www.v-signon.com_ecc/www.v-signon.com.cer;
        ssl_certificate_key /root/myacme/ssl/www.v-signon.com_ecc/www.v-signon.com.key;

        location / {
                rewrite ^/(.*)$ https://v-signon.com/$1 permanent;
        }
    }
    
    ————www.v-signon.com学习者共勉