The Project Charter is somehow the result of the qualification phase (i.e. the three firsts stages). It’s a document which gathers all the information given by the business and can also be amended all along the project duration. It may also be used as a specification and why not for contractual purposes, but in this case it would need to clarify the governance rules and policy around this document.
At the end of each stages of the ExYPro Methodology (from 1 to 3) :
we’ll propose (the information form) a way to specify what would be needed in the project charter (a kind of summary).