The app stores have strict policies on what content is allowed in the app. Here are some link types that aren't acceptable to open within the app:
YouTube links or embeds that allow you to get to YouTube
Giving
Purchases
References to the app store companies or stores in any capacity (ex. a Google Play logo or picture of an iPhone)
Features that require logins
References to the pandemic in any capacity
Any way to get to any of the above (ex. if a website links to Facebook, which links to YouTube, then it counts as having YouTube)
However, if you know that the URL you are linking to has no way for your user to make a transaction, then it is safe to use!
Are you using SnapPages to build and host your website? SnapPages will automatically hide the navigation bar, header, and footer from your website, ensuring that your app complies with the App Store policies and guidelines.