Locus map as default maps app for Garmin Messenger and other apps?

Not sure if this is possible or not...

Setup: Samsung A54, Locus Maps 4.31(Auto) via APK load, Gold

I have a Garmin satellite (Iridium) messenger, the app it uses always has the coordinates of the person I am corresponding with. When I hold on the "pin" in messenger it offers me a choice of showing the location in Google Maps or Garmins own Explore app - see image.

What I am trying to do is make Locus maps (and indeed other apps I have Like the UK Ordanance Survey one) appear in the list of options I can show the location in.

If I look in Android settings I can set Locus as the default for many types of link,

I have tried turning on all of these but Locus does not appear as an option in messenger.

If I look at the settinge for the Garmin app that does appear it has different URL's

I tried to add these URL to the default settings of Locus, but it does not seem possible, perhaps they are set at compile time?

Does anyone know how I can do this? the fact Google maps appears as an option must mean it's possible to use non Garmin apps to show the location, so why not Locus?