Just to point this out to anyone looking for this ,
it took me a quite a bit of search to get this going ,
and found this on one of the links on this forum,
which is absolutley great ,
you point your shotgrid desktop to 3
by adding this env to
export SHOTGUN_PYTHON_VERSION=3
and for the shotgrid interpreter ,
in the interpreter config to
Path_To/Shotgun/Python3/bin/python3.7
and that should get you running 3.7 with shotgrid,
and for the dccs point them to 3.7 shotgrid
hope this helps