Log in to Google Ads > "Tools & Settings" (1) > "Conversions" (2)
Ideally, you should NOT have the same conversion event marked as "Primary" twice (1). You need to change one of them to "Secondary".
Click the conversion you want to change (2).
Click on "Edit Settings" at the bottom-left corner.
Click on "Goal and action optimization".
Choose "Secondary" or "Primary" depending on what you are trying to achieve (1). Then click "Save" (2).
You can also change your attribution model in here, as the "Last click" option is never ideal.
We recommend the "Position Based" option. You can learn more about why we recommend this in here.
Select "Position based" (1), click "Save" (2), and then click "Done" (3) after you are done with the changes.
Go back to conversions by clicking "Conversions" at the top.
Check if the changes have been applied.