Import data tier application in Managed instance
Try using SqlPackage instead:

sqlpackage.exe /Action:Import /tsn:MyServer /tdn:worldwide /tu:MyUserName /tp:MySecretPwd /sf:c:\sql\WideWorldImporters-Standard.bacpac 


The command will import the bacpac file to Azure. The parameters used are the following: 

/Action is used to indicate if we are going to import, export, publish, and extract data. 

/tsn is used to define the Target Server Name. 

/tdn is the name of the new database to be created. 

/tu is the Target User. It is the Server Admin Login.

/tp is the Target Password. It is the password defined.

/sf is the source file.