I asked which Dynamics 365 software you need to work, your question is not clear, from your latest reply maybe you need to move data from HI-KORT (it's related to SAP?) to Dynamics 365?
Dynamics 365 can identify different products:
Dynamics 365 (CRM, CE/Customer Engagement) it's a software based on Dataverse
Dynamics 365 F&O (Finance & Operations, new version of Dynamics AX) is an ERP software
there is also Business Central (new version of Dynamics NAV) that is also an ERP as well.
Let's say you need to migrate 2 million records from HI-KORT to Dynamics 365 CE (based on Dataverse) doable with Dataverse API but with that amount of data Power Automate is not the answer if you need to migrate this data in a reasonable amount of time, you should look at other tools like Azure Data Factory or SSIS (SQL Server Integration Server) with a tool like KingswaySoft