We use Google
I'm not sure I understand what you mean by "However, I couldn't find the plugin in Safari on websites. Is this normal?" however, Safari, like other browsers, blocks Flash by default. See https://helpx.adobe.com/flash-player/kb/enabling-flash-player-safari.html for assistance enabling Flash in Safari
Apple dropped support for the Flash plug-in in the Safari 14 update. You'll need to use a different browser if you need to access Flash-based content.