Hi @frankderuyck,
If you're interested about the validation method behind SVEM and its use for various modeling platforms, you can use autovalidation table or use the SVEM add-in, as explained in my answer to one of your previous post SVEM ADD IN FOR SUPPORT VECTOR MACHINE SVEM (Forward Selection) is also one of the default estimation method available in the Generalized Regression platform.
Besides these (free) options, the add-on shown in your capture is a product you can buy from Predictum, as mentioned by @txnelson : https://predictum.com/products/svem
Hope this answer will help you,
Victor GUILLER
"It is not unusual for a well-designed experiment to analyze itself" (Box, Hunter and Hunter)