The best way, or course, is to write them, and explain the intended use, and ask what is needed for to get permission. Offer to include a link, a credit, and describe what use you wish to make of the image. Some photographers will give permission for merely a link and a credit. Others will want to be paid.
What happens after 10k followers on Instagram?
Once you have 10k followers, Instagram will make it easier for you to get people to your website via Stories with the swipe up to link feature. Swipe up is the only way to get a direct link from your Instagram to your other web properties. And, it’s available in STORIES, if you have 10k followers.