Unable to resolve class SpinXmlTreeElement

Hi there,
I am trying to work with XML but there’s no class that works for me, from this guide:

If I don’t specify a class the error goes away, but I still cannot .append child elements because they become separate XML elements.

import static org.camunda.spin.Spin.XML;

SpinXmlTreeElement root = XML("<root/>");

SpinXmlTreeElement child1 = XML("<child/>");
SpinXmlTreeElement child2 = XML("<child/>");
SpinXmlTreeElement child3 = XML("<child/>");

root.append(child1, child2, child3);

I’m not a programmer but a business analyst and cannot access the library since I have no IDE. Hope somebody could help me. Have a good rest of the day!

I’ve included all of the following libraries:

and then used the following code:

Therefore, “SpinXmlElement” class has to be used, instead of “SpinXmlTreeElement”. I’d like to ask Camunda to update their manual on this link: