I am getting this error when installing to an (almost) fresh instance of Debian Buster 10:
TASK [funkwhale : Install certbot snap] ******************************************************************
fatal: [127.0.0.1]: FAILED! => {"changed": true, "cmd": ["snap", "install", "--classic", "certbot"], "delta": "0:00:00.482271", "end": "2021-07-21 11:36:41.758145", "msg": "non-zero return code", "rc": 1, "start": "2021-07-21 11:36:41.275874", "stderr": "error: snap \"certbot\" is not available on stable but is available to install on\n       the following channels:\n\n       edge       snap install --edge certbot\n\n       Please be mindful pre-release channels may include features not\n       completely tested or implemented. Get more information with 'snap info\n       certbot'.", "stderr_lines": ["error: snap \"certbot\" is not available on stable but is available to install on", "       the following channels:", "", "       edge       snap install --edge certbot", "", "       Please be mindful pre-release channels may include features not", "       completely tested or implemented. Get more information with 'snap info", "       certbot'."], "stdout": "", "stdout_lines": []}

PLAY RECAP ***********************************************************************************************
127.0.0.1                  : ok=32   changed=4    unreachable=0    failed=1    skipped=16   rescued=0    ignored=0