Google Search Console is flagging increasing number of pages on my website with the message "The tag ‘img’ should be replaced with an equivalent ‘amp-img’ tag". The pages being flagged are old blog posts from many years ago but which are still getting traffic. Obviously they weren't AMP optimised back then and the problem is arising now as those pages get freshly crawled. Is this a problem that can be easily fixed or will I need to hire a freelancer? I'm reasonably proficient with SS but I don't have sufficient technical knowledge to do backend work on my site.