You appear to be using the Firefox web browser on Android to post this question.

In case you are referring to the Google search engine in Firefox then see https://support.mozilla.org/en-US/kb/manage-my-default-search-engines-firefox-android

If you are referring to making Firefox as the default web browser on Android then see https://support.mozilla.org/en-US/kb/make-firefox-default-browser-android

Step 1 — Download Firefox

Open the Google Play Store on your Android Search for Firefox Tap Install and wait for it to download

Step 2 — Set Firefox as Your Default Browser

Open your Settings app Tap Apps (or Apps & Notifications on some phones) Tap Default Apps Tap Browser App Select Firefox from the list

That is it — Firefox is now your default browser.

What this means:

Any link you tap — in emails, messages, or other apps — will now open in Firefox instead of Chrome Chrome will still be on your phone but will no longer open automatically You can still open Chrome manually whenever you want

Extra Tips:

When you first open Firefox, it may ask if you want to set it as your default browser — just tap Set as Default to do it quickly You can also import your bookmarks and saved passwords from Chrome into Firefox during the setup If you do not see Default Apps in your settings, try searching for "default browser" in the Settings search bar — the exact location varies depending on your Android phone brand