Webview upload image

I built an app for the site with webview and extension called custom web view, and because the site itself is a forum so you have to upload pictures and videos, how do I do that as soon as a user clicks on the option to upload a video / image it will open the gallery and select an image and upload to the site … (I know Which needs permissions and it’s relatively simple … because it’s actually a site … that’s why I asked … I would love to help)

Sorry for the delay in my response.
What permissions do I need for this?

hello I followed the tutorial but I encounter an error “Cannot find the component: FilePicker1”