Google ad extensions are being rebranded as assets

Existing ad extensions will automatically transition to assets while maintaining associations at the account, campaign and ad group levels.

Google just announced that ad extensions will be rebranded to assets in the Google Ads UI. The change will be rolled out over the next couple of weeks.

Source - https://searchengineland.com/google-ad-extensions-are-being-rebranded-as-assets-387983