There is no direct way to change a user's email address that was already used to invite them to ApprovalMax, as this email address is tied to the user's identity.
However, the Administrator can use one of the following workarounds:
Solution 1
The Administrator creates a new user account for this person with a different email address and invites them.
Once the invitation is accepted, the Administrator removes the old user account, effectively offboarding the user under their previous profile, and specifies a new user account as a replacement.
Please note: Users who join under a new email address won't see any old requests.
Solution 2
The user leaves the old email address in their ApprovalMax profile and - in the settings of their email client - sets up a redirection rule to their new email address.
Please note: Users will need to use their old email address to log in to ApprovalMax.