The operation is insecure

When i open the website which is test the vtkjs in the firefox, the page can not show normally, and there are something errors like in the picture.
and the chrome can not show normally too, but the errors are not the same.
I try to set the firefox, it is invalid. what happened?

I am still troubled by this problem. Does anyone encounter such a problem ?

Could you explain what you are doing in order to get those error?
Are the examples on the web site working in your browser?

Thank you, I will try to config the examples on my computer. But the website works well on the Edge.