Question for those who use Instagram Feed plugin or similar on WP-theme demo site

Hello.

We are WordPress theme developers. We want to use our Instagram images (through Instagram Feed plugin) on our demo site. Instagram account is our and we are the authors of images. But these images are third-party resources for our demo site, so we need to specify copyright and license to them in theme docs. With copyright all is clear, because we are the authors of images. But we have some difficulties with specifying of License. On Instagram site we could not find a clear answer.

Can you tell us, what License is used to Instagram content?