Warnings in Qualys SSL Server Test - caused by long chain?

This is what I mean by without success:

$ sudo certbot --preferred-chain "ISRG Root X1"
usage:
certbot [SUBCOMMAND] [options] [-d DOMAIN] [-d DOMAIN] ...

Certbot can obtain and install HTTPS/TLS/SSL certificates. By default,
it will attempt to use a webserver both for obtaining and installing the
certificate.
certbot: error: unrecognized arguments: --preferred-chain ISRG Root X1

nginx conf references cert/chain this way:
ssl_certificate /etc/letsencrypt/live/paninikidreporter.com/fullchain.pem; # managed by Certbot
ssl_certificate_key /etc/letsencrypt/live/paninikidreporter.com/privkey.pem; # managed by Certbot
include /etc/letsencrypt/options-ssl-nginx.conf; # managed by Certbot
ssl_dhparam /etc/letsencrypt/ssl-dhparams.pem; # managed by Certbot

Ubuntu 18.04.6 LTS
certbot 0.31.0
nginx/1.14.0