Generally the Snyk Language Server will update automatically in IDEs that require it, but in some cases you may need to force it to update - for instance if you have previously overridden the automatic updates, or if you are experiencing issues that may be language server related.
The steps to force the use of the latest language server are found in the Snyk User Docs at https://docs.snyk.io/scm-ide-and-ci-cd-workflow-and-integrations/use-snyk-in-your-ide/troubleshooting-ides/force-use-of-the-latest-language-server