Sale of goods by URP

Dear sir,

We are a charitable trust registered under Indian trusts act and are an Unregistered person ((URP) under GST.

We had purchase some scaffolding material for construction activities in our trust of Rs 5 crs and now wish to sell them as that activity has concluded.

How can we sell these items without generating invoice (as we don't have GST number)? We can generate delivery challan and e-way bill. But how will the buyer be able to claim GST if we don't raise an invoice.?

Please advise.

Regards