how implement this equation in FEATOOL?

How implement this equation in featool ??

(∂T/∂t) −κ∇ 2T = 0

thankss!

[Precise Simulation]

If this is equivalent to typical heat conduction with time dependent term and conduction with conductivity 'kappa' your can use the standard heat transfer physics mode (set both rho and Cp to 1) and just ignore/skip the convective and source terms (default zero):

Definition of the heat transfer physics mode in FEATool Multiphysics