When a method provided by the browser is marked as deprecated, it is necessary to intervene in the code in order to change the method for an alternative to ensure future compatibility. If this code comes from the use of a third party module, it is then necessary to update it or to find a more modern alternative.
Deprecated methods appear as a warning in the Chrome browser console. Here is a warning on the presence of an obsolete method whose use will soon change :
speechSynthesis.speak() : speechSynthesis.speak() without user activation is no longer allowed since M71, around December 2018. See https://www.chromestatus.com/feature/5687444770914304 for more details