Is it possible to create one invoice for multi projects

I don't know if this will help Invoice Groups Overview

There's an accounting preference that puts the project in the Invoice in the transaction lines allowing you to invoice multiple projects from the same customer and subsidiary and with the same currency in a single invoice. Test extensively as this may affect a lot of other functionalities and probably any customization in your NS account.

You mean to say enabling group invoice

No. I meant Consolidate Projects on Sales Transactions

Thank you for the solution