According to your mobile version, open the Play Store or the App Store.
Then, go to the search address bar and type 'Webroot.'
After that, the list of products will show.
Hence, select the product to fulfill your security needs.
Then, tap on the 'install' button.
This will start the downloading process.
Hence, tap on the 'open' button to launch the app.
Now, a window will turn up on the screen showing the installation agreement.
Click on the link and read the document attentively.
Further, click on the 'agree & launch' button.
As a result, the pop-up box asking your authorization to access media, photos, and other files will appear.
You have to click on the 'allow' button.
Further, a new window will project on the screen with two options stating 'activate' and 'skip.'
First-time users can start the free-trial version here by clicking on the 'skip' button.
However, for the paid version, tap on the 'activate' option.
Now, type the activation code and click on the 'ok' button.
Further, a success pop-up will appear. Now, you can activate the settings for the security of your phone.