How do you get rid of the shipping weight warning

Hi, every time we test adding a product to cart we get this message:

Warning: A non-numeric value encountered in /home/customer/www/stephaniei1.sg-host.com/public_html/wp-content/plugins/official-sendle-shipping-method/joovii-sendle-shipping.php on line 308

I believe it’s due to the weight value being 0 however we have over 100 products so wondering if its possible to bypass this but inputting a code?

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