pveam available
returns:
mail proxmox-mailgateway-6.4-standard_6.4-1_amd64.tar.gz system alpine-3.11-default_20200425_amd64.tar.xz system alpine-3.12-default_20200823_amd64.tar.xz system alpine-3.13-default_20210419_amd64.tar.xz system archlinux-base_20210420-1_amd64.tar.gz system centos-7-default_20190926_amd64.tar.xz system centos-8-default_20201210_amd64.tar.xz system debian-10-standard_10.7-1_amd64.tar.gz system debian-9.0-standard_9.7-1_amd64.tar.gz system devuan-3.0-standard_3.0_amd64.tar.gz system fedora-32-default_20200430_amd64.tar.xz system fedora-33-default_20201115_amd64.tar.xz system fedora-34-default_20210427_amd64.tar.xz system gentoo-current-default_20200310_amd64.tar.xz system opensuse-15.2-default_20200824_amd64.tar.xz system ubuntu-16.04-standard_16.04.5-1_amd64.tar.gz system ubuntu-18.04-standard_18.04.1-1_amd64.tar.gz system ubuntu-20.04-standard_20.04-1_amd64.tar.gz system ubuntu-20.10-standard_20.10-1_amd64.tar.gz system ubuntu-21.04-standard_21.04-1_amd64.tar.gz turnkeylinux debian-10-turnkey-ansible_16.1-1_amd64.tar.gz turnkeylinux debian-10-turnkey-asp-net-core_16.1-1_amd64.tar.gz turnkeylinux debian-10-turnkey-avideo_16.1-1_amd64.tar.gz turnkeylinux debian-10-turnkey-b2evolution_16.1-1_amd64.tar.gz turnkeylinux debian-10-turnkey-bagisto_16.1-1_amd64.tar.gz turnkeylinux debian-10-turnkey-bugzilla_16.1-1_amd64.tar.gz turnkeylinux debian-10-turnkey-cakephp_16.1-1_amd64.tar.gz turnkeylinux debian-10-turnkey-canvas_16.2-1_amd64.tar.gz turnkeylinux debian-10-turnkey-codeigniter_16.1-1_amd64.tar.gz turnkeylinux debian-10-turnkey-collabtive_16.1-1_amd64.tar.gz turnkeylinux debian-10-turnkey-concrete5_16.1-1_amd64.tar.gz turnkeylinux debian-10-turnkey-core_16.1-1_amd64.tar.gz turnkeylinux debian-10-turnkey-couchdb_16.1-1_amd64.tar.gz turnkeylinux debian-10-turnkey-django_16.1-1_amd64.tar.gz turnkeylinux debian-10-turnkey-dokuwiki_16.1-1_amd64.tar.gz turnkeylinux debian-10-turnkey-domain-controller_16.1-1_amd64.tar.gz turnkeylinux debian-10-turnkey-drupal7_16.1-1_amd64.tar.gz turnkeylinux debian-10-turnkey-drupal8_16.1-1_amd64.tar.gz turnkeylinux debian-10-turnkey-drupal9_16.1-1_amd64.tar.gz turnkeylinux debian-10-turnkey-e107_16.1-1_amd64.tar.gz turnkeylinux debian-10-turnkey-elgg_16.1-1_amd64.tar.gz turnkeylinux debian-10-turnkey-espocrm_16.1-1_amd64.tar.gz turnkeylinux debian-10-turnkey-etherpad_16.1-1_amd64.tar.gz turnkeylinux debian-10-turnkey-ezplatform_16.0-1_amd64.tar.gz ...
For example basic system images:
pveam available --section system
returns:
system alpine-3.11-default_20200425_amd64.tar.xz system alpine-3.12-default_20200823_amd64.tar.xz system alpine-3.13-default_20210419_amd64.tar.xz system archlinux-base_20210420-1_amd64.tar.gz system centos-7-default_20190926_amd64.tar.xz system centos-8-default_20201210_amd64.tar.xz system debian-10-standard_10.7-1_amd64.tar.gz system debian-9.0-standard_9.7-1_amd64.tar.gz system devuan-3.0-standard_3.0_amd64.tar.gz system fedora-32-default_20200430_amd64.tar.xz system fedora-33-default_20201115_amd64.tar.xz system fedora-34-default_20210427_amd64.tar.xz system gentoo-current-default_20200310_amd64.tar.xz system opensuse-15.2-default_20200824_amd64.tar.xz system ubuntu-16.04-standard_16.04.5-1_amd64.tar.gz system ubuntu-18.04-standard_18.04.1-1_amd64.tar.gz system ubuntu-20.04-standard_20.04-1_amd64.tar.gz system ubuntu-20.10-standard_20.10-1_amd64.tar.gz system ubuntu-21.04-standard_21.04-1_amd64.tar.gz