Add a georeferencing constraint in XLSForm

1. What is the issue? Please be detailed.

I will like to solve a problem with a constrain in ODK!
I have to georeference trees in a restricted area and fill some informations. I have about 1100 trees .
I want make sure trees that are georeferencing, have their coordonnate inside the restricted area.
for exemple the retricted area has coordonnate(X;Y): ((40;100),(90;70),(70;40);(22;25)).

His anybody know how to make a constrain so that every coordonnate must be located in the polygon of the restricted area???

I am new ,and very news to ODK.

THANK YOU

Welcome @KTU_DESIRE,
Maybe the "showcase" can help you: ODK geofence (v1).
Further hints could be found with the search function of the forum, see e.g. https://forum.getodk.org/search?q=geofencing (and https://forum.getodk.org/search?q=georeferencing).