After installing the extension, I disabled checking in all websites because I want to opt-in, and not opt-out of LanguageTool.
However, I found out that with this setting, I lost the browser’s default spellchecking in all sites. So either I don’t have any spellchecking at all (because LanguageTool is not enabled in that website AND it somehow disabled the browsers default spellchecking) OR I have it on for all websites.
Is there a way to fix this?