Hi @shantee,
Right now the only way to do this for some of the supported material channels (e.g. diffuse, normal), is by using FBX models. Check this short guide:
https://developer.playcanvas.com/en/user-manual/assets/models/exporting/
There is support coming for importing gITF models in the editor, when that comes importing fully textured models with exact material settings will work way better: