Accessing shell thickness in UMAT/VUMAT

I would like to access shell thickness in UMAT/VUMAT routines in ABAQUS 2018-2025 but cannot find a solution in the users' manual.

 

The utility routines GETVRM/VGETVRM seem promising but do not seem to support the relevant output variable STH.

 

I would be very grateful if someone could provide me with a solution