Undefined array in error log

In the wordpress error_log I see lots of these message lines below, these are just a few, there many more undefined array keys error lines:

Undefined array key “pagination” – line 385

Undefined array key “layout” – lines 418, 360, 361

Undefined array key “content” – line 301

Undefined array key “class” – line 328

public_html/wp-content/plugins/strong-testimonials/includes/class-strong-view-display.php

php8.1, wordpress 6.4.2, strong testimonials 3.1.11