The optimization example's plot is blank

[rs-bh-n]

Description of the modifications

The expected plot is not showing in docs : https://dyna.docs.pyansys.com/version/dev/examples/Optimization/Plate_Thickness_Optimization.html#generate-graphical-output

Shows :

Expected :

Useful links and references

https://dyna.docs.pyansys.com/version/dev/examples/Optimization/Plate_Thickness_Optimization.html#generate-graphical-output