Can we utilize import management feature just to load Milestone planning tab only

As per note:

We can create milestone for contract lines using

 Project Contract Billing: Milestones import object in the import management framework.

However, we would like to understand, if we can create a new contract from template and utilize only milestone import object to import milestones only into draft contract and submit for approval?

We have tried to load but getting errors as attached in the sheet, prepared for import.

Extract from above note applicable for this question:

"Milestone Maintenance Using File-Based

Data Import

Create, update, or delete milestones for contract lines in bulk using the Project Contract Billing: Milestones import object in the import management framework. Use the associated CSV file template to create new milestones for a contract line, or add existing project plan milestones to a contract line.