This article explains how to replace the native search bar in the Astra theme by Brainstorm Force.
FiboSearch plugin features built-in integration with this theme. It means you can replace the default search bars by selecting a single checkbox.
If you have activated the Astra theme or the child theme of Astra theme, you should see the following screen in the plugin settings:
Select the option
Replace all Astra search bars with FiboSearch and the search bar should be replaced.