JSFiddle - React, Tailwind, and code Playground

HTML

<p class="fp-excerpt fp-text-one  text-random-override">[image caption]I don't want this text[/image caption]Lorem Ipsum Text</p>

<p class="fp-excerpt fp-text-one  text-random-override">[image caption]I don't want the text here too[/image caption]Lorem Ipsum Text number two</p>

JavaScript

$(".text-random-override").each(function() {
  $(this).html($(this).html().replace(/\[image caption\].+\[\/image caption\]/g, ""));
});