Critical error after clicking publish/save as draft for woo products

I am working on a woocommerce website. I am using the latest version of wordpress, woocommerce and transdirect shipping. I am seeing the error below when pressing draft or publish products.

These are the last 3 lines of error log from a website.

[07-Feb-2024 08:31:36 UTC] PHP Warning: Trying to access array offset on value of type null in /home/argiegri/public_html/wp-content/plugins/transdirect-shipping/transdirect_shipping.php on line 601 [07-Feb-2024 08:31:56 UTC] PHP Warning: Trying to access array offset on value of type null in /home/argiegri/public_html/wp-content/plugins/transdirect-shipping/transdirect_shipping.php on line 601 [07-Feb-2024 08:39:45 UTC] PHP Warning: Trying to access array offset on value of type null in /home/argiegri/public_html/wp-content/plugins/transdirect-shipping/transdirect_shipping.php on line 601

Can you help me please?