Recently i had request to invite external user to Azure Application but not to send invitation to user email address
Open Powershell:
Connect-AzureAD -credential New-AzureADMSInvitation -InvitedUserEmailAddress "user@example.com" -SendInvitationMessage $false -InvitedUserType "Member" -inviteRedirectUrl "https://application.com"
InvitedUserType: Member or Guest
Then copy InviteReedemUrl and send it to requester