Google added a discover report to Google Search Console back in April. But the only way for you to see that report, as we said back then, was to have enough data (impressions/clicks) within the Google Discover feed for Google to report it within Search Console.
But not having that Discover tab in Search Console is not a sign that your site is not trusted by Google. It just means your site and content may not be relevant for the Google Discover feed.
John Mueller from Google said on Twitter "It's not a quality judgement -- it's basically just that we don't have enough data for your site in the Discover feed."
Here are the tweets with context around this message:
It's not a quality judgement -- it's basically just that we don't have enough data for your site in the Discover feed (similar to how we don't show different structured data types if we don't have data for your site for them).
— 🍌 John 🍌 (@JohnMu) July 16, 2019
So do not worry if you do not see this tab in Search Console. It is really meant for news related content.
Forum discussion at Twitter.