SearchMeter Plugin causing website errors

With the searchmeter plugin version 20.9.1. activated, I receive the following error message on my website (front and backend) appearing above the website:

Notice: The called constructor method for WP_Widget in SM_Popular_Searches_Widget is deprecated since version 4.3.0! Use

__construct()

instead. in /nas/content/staging/cyberseer/wp-includes/functions.php on line 3894

Notice: The called constructor method for WP_Widget in SM_Recent_Searches_Widget is deprecated since version 4.3.0! Use

__construct()

instead. in /nas/content/staging/cyberseer/wp-includes/functions.php on line 3894

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I’ve spoken to my theme (total) developers and they said the searchmeter plugin hasnt been updated in the last 9 months and this means a lot because WP has changed a lot in all this time.

Note I’ve been looking at this on my staging site (https://cyberseer.staging.wpengine.com/) so that my live website is not affected.