bryantmilan @Hari
The following applies according to their website
If you are using Imgur to host images for a site that makes money, whether from ads or any other way, it's considered to be commercial. This is against our Terms of Service (TOS) and images found to be used this way may be blocked. For more details, please read our TOS.
Essentially, this means that if your site charges a fee or makes money, then it's classed as commercial. This then violates the free API agreement. It's made abundantly clear here
Also, don't use Imgur to host image libraries you link to from elsewhere, content for your website, advertising, avatars, or anything else that turns us into your content delivery network. If you do – and we will be the judge – or if you do anything illegal, in addition to any other legal rights we may have, we will ban you along with the site you're hotlinking from, delete all your images, report you to the authorities if necessary, and prevent you from viewing any images hosted on Imgur.com. We mean it.
You can leverage your own cheap CDN for this purpose. Have a look at BunnyCDN for example for very favourable packages. The one downside to this is a lack of push/pull content in terms of CDN deployment in Flarum, but it's arguably much less hassle that a legal suit.
