Saving custom models

[ArturoBG]

Hello
I am currently having a lot of fun with this amazing assets, but a i have a question that might be something super easy however im failling to notice why.
Whenever i try to save a custom 3d model, for example a ".obj", the error:
"Not allowed to access vertices on mesh 'model' (isReadable is false; Read/Write must be enabled in import settings"
According to Unity Documentation is bad to enable that at runtime, so it should be disabled.
Can anyone help me to get a workaround to this issue?? could it be solved with your asset?
Thanks in advance!