Can't make solid object for meshing

I am an absolute beginner at SketchUp. I have created a CAD drawing using SketchUp free web version and want to turn it into a solid object using group and then want to mesh it for OpenFOAM. I can’t use the solidinspector2 plugin since I am using the free version. I highly appreciate your help how to solve the issues using the free version. I am attaching a link to my files. Thanks.

A ‘Solid’ objected must consist of a single group or component-instance.
This ‘container’ must contain only edges and their associated two faces [i.e. no faceless, one faced or >2 faced edges].
So no ‘nested’ things like other groups or instances…
Your model contains the default 3d-figure which your should delete.
It all has several nested groups with groups.
If you select those using the Outliner, and explode them them the single group you have remaining will be a ’ Solid’ !

I’ve done that and your model is now proper ‘Solid’…

Thank you so much for your solution. Would you please tell me how to delete the default 3d-figure? I am confused which one is the default 3d-figure.
Can I select the whole thing by clicking three times and explode it? is it the same? I am using the free windows web version. Thank you.

I got you, I have deleted the human figure. Now, need to use the Outliner and explode them. I will let you after figuring it out. Thanks.

In order to use the outliner, I will have to upgrade the SketchUp version. Thanks for your solution.