In the upload form, open the Advanced panel:

  1. Save configuration to use again: give it a name, choose whether it applies to all your accounts or only this account, select the fields (main text, headline, website, UTMs, button) and save.
  2. On future uploads, open Use saved configuration, choose the configuration and click Apply configuration. The screen shows what will be replaced before it applies.
  3. Changed your defaults? Select the configuration and click Update configuration: it's overwritten with the current fields, without creating a new one. Delete configuration removes it.

The individual texts from Edit each ad aren't included in the saved configuration (they only apply to the current upload).