Did you try to run the Lighthouse report from the developer console in Google Chrome? If not, you could try this. Just open your page in Chrome, press F12, go to the Lighthouse tab and click 'Analyze page load'. It will check your page regarding SEO, accessibility, performance etc. and will give you a score and tell you quite detailed what you need to add/update to make it score higher. I did that for my own website https://teamquiz.dk and it gave me a lot of hints to missing tags in the head section of pages etc.