You could also use kdeconnect-cli. Typically something like:
If needed:
kdeconnect-cli -l
kdeconnect-cli --pair -d XXX
then
kdeconnect-cli -d XXX --share 'path/to/file'
Where XXX is device-id (16 char hex string).
Beyond:
Using GNOME one can add GSConnect
On Plasma I unfortunately have had some issues finding a good interface for SMS, but I might be missing something.
From the "Start Menu" one typically have something like:

Entering “Mobile Settings” I have:

Where I can set custom path for received files, and then also set up scripts for that folder (inotify etc.) One can also set up commands etc.
Notifications are sent to desktop (SMS, calls, etc.). I have KDE/GS icon in my head bar:


Which has a decent SMS GUI interface, share files option etc. Clicking the share icon at the end opens a file selector where file(s) to be sent can be selected.
On the side:
It's easy to hack SMS by using
.cache/gsconnect/XXX/sms.json
.cache/gsconnect/XXX/contacts.json
where XXX is device ID.
which again can be used with ckdeconnect-cli if one desire.