nextcloud snap fails to enable https

his is what I get from the terminal:

panagiotis@pop-os:~$ sudo nextcloud.enable-https lets-encrypt
[sudo] password for panagiotis:
In order for Let's Encrypt to verify that you actually own the
domain(s) for which you're requesting a certificate, there are a
number of requirements of which you need to be aware:

    In order to register with the Let's Encrypt ACME server, you must
    agree to the currently-in-effect Subscriber Agreement located
    here:

    https://letsencrypt.org/repository/

    By continuing to use this tool you agree to these terms. Please
    cancel now if otherwise.

    You must have the domain name(s) for which you want certificates
    pointing at the external IP address of this machine.

    Both ports 80 and 443 on the external IP address of this machine
    must point to this machine (e.g. port forwarding might need to be
    setup on your router).

Have you met these requirements? (y/n) y
Please enter an email address (for urgent notices or key recovery): ******@****.com
Please enter your domain name(s) (space-separated): *********.ddns.net
Attempting to obtain certificates... error running certbot:

An unexpected error occurred:
IOError: [Errno 13] Permission denied: '/etc/os-release'
Please see the logfile '/tmp/tmpki87mT' for more details.

When I try: $ sudo snap run --shell nextcloud.enable-https -c 'cat /etc/os-release'
I get: cat: /etc/os-release: Permission denied

When I try:
ls -ld /etc/os-release
I get: rwxrwxrwx 1 root root 17 Μαΐ 15 02:38 /etc/os-release -> pop-os/os-release

When I try: cat /etc/pop-os/os-release
I get: NAME="Pop!_OS" VERSION="20.04 LTS" ID=pop ID_LIKE="ubuntu debian" PRETTY_NAME="Pop!_OS 20.04 LTS" VERSION_ID="20.04" HOME_URL="https://system76.com/pop" SUPPORT_URL="http://support.system76.com" BUG_REPORT_URL="https://github.com/pop-os/pop/issues" PRIVACY_POLICY_URL="https://system76.com/privacy" VERSION_CODENAME=focal UBUNTU_CODENAME=focal LOGO=distributor-logo-pop-os