(1) The user has a role which doesn't have the rights to execute TravelAgencyx.GetCurrentAccount.
First check what module roles are checked for the Microflow TravelAgencyx.GetCurrentAccount. Then check if one of those roles is checked for the user roles associated to your user (Project -> Security -> User roles tab -> Edit button.
(2) If you are deploying in a sandbox, you should login with your Mendix account. If not, can you provide more information about your setup? Do you mean MxAdmin when you mention admin account, for example?