DAX formula

Hi all, I am new to powerBI and fabrics. My task is to export the powerBi data which is present in the fabrics workspace into csv file. I am trying to create a power automate flow to do this. But i got stuck in "Run a query against dataset" action. I am not sure exactly how to write the DAX function. kindly help. 

Table1:                                                                  Table2:
Firstname                                                               Orderno
Lastname                                                                Enteredby

Sex                                                                          Commends
DOB
City
State                                                                                      
I used thesse column values from Table1 and Table2 and created a table visual. Thanks in advance!