Do you have protocol documentation?
No sorry I don't.
I just have this link : https://buy.garmin.com/sv-SE/SE/p/592606
You would have to get documentation. Most likely the answer is NO though.
The protocol doc is here:
http://files.delorme.com/support/inreachwebdocs/IPC_Outbound.pdf
Yes, the built in Garmin tracking site is pretty bad :) https://goo.gl/gtPMwX
I asked about this in 2017 and it wasn't supported at that time.
It doesn't seem to be supported.
I wonder if you know if the traccar server supports the Garmin Inreach Mini devices?