This article explains how to turn off JavaScript in the desktop version of the Opera browser.These directions are confirmed to work for Opera 112 but can probably be adapted for other versions.
How to Block a WebsiteOpera has two settings related to JavaScript.Follow these steps to disable JavaScript across all sites or pick specific websites that aren't allowed to use it.
Select theOin the corner to open the menu, then chooseSettings.
SelectPrivacy & securityon the left, thenSite settingson the right.
SelectJavaScript.
ChooseDon't allow sites to use JavaScriptto block it on all web pages. Or, for fine control over which sites are allowed to use JavaScript, selectAddnext to the Now Allowed or Allowed section and specify the URL.