Also I took a quick look at your latest uploaded snap - to use the system-files interface you can’t just declare plugs: system-files - please take a closer look at the documentation for this interface at The system-files interface.
Instead you need to define a system-files plug for your own snap which declares what file paths are being accessed and what permissions are being used and you need to give that interface a nice user-understandable name - for instance you could use something like the following if you need just read access to this file:
plugs:
run-systemd-resolve-resolve-conf:
interface: system-files
read:
- /run/systemd/resolve/resolve.conf
apps:
network-sports-icarus:
plugs:
- run-systemd-resolve-resolve-conf
...
If however you wish to have read+write access then change the read: to write:.
But can you please elaborate on why your snap requires access to this file and for what purpose so we can properly understand this request? Thanks.