It is essential, especially for health. As far as recommendations, the one I am most familiar with is 20-30g a day (female/male). One thing you want to monitor with this is transient time. The most basic way to do this is eat sesame seeds. If you pass them the next day, you’re good, eat a maintenance level of fiber. If you dont pass it for more than 1 day, you may want to look into increasing fiber intake which helps regularity. Being regular has a large impact on your gut bacteria and flora, so if your food is sitting around in your system longer than it needs to it will start to create dysbiosis