If you are posting your work online and there’s a place where you can get feedback on it (for example, on wattpad that’s the comments section under each of your chapters), reply to that feedback. Interacting with people might encourage them to comment again and silent readers are more likely to speak up, if they know you are reading the comments.
But what if it is negative feedback?
Well, there are two types you can call “negative” – trolls/bullies leaving comments and sentences like “Your story needs a lot of editing”. This topic is a rather long one so I’ll write about it outside of the TTWT series (but still in the Writing Tips & Prompts section), but just so you’ll know, “Your story needs a lot of editing” might be the most useful feedback you get.