You cannot create a personal account in a tenant, you can only invite a personal account to the tenant as a guest.
You can invite directly in the Azure portal or through the graph API.
Through the Azure portal:
Through the graph API:
POST https://graph.microsoft.com/v1.0/invitations
Content-type: application/json
{
"invitedUserEmailAddress": "******@fabrikam.com",
"inviteRedirectUrl": "https://myapp.contoso.com"
}
Hope this helps.
If the reply is helpful, please click Accept Answer and kindly upvote it. If you have additional questions about this answer, please click Comment.