Webflow

Everything is done from Site settings and the Designer; the site must be published to a domain for robots.txt and custom code to go live.

1.robots.txt: open Site settings > SEO > Indexing and paste the generated robots.txt content into the robots.txt field, replacing the existing rules. Save, then republish the site: Webflow serves it at /robots.txt.
2.llms.txt: in Site settings > SEO, if your workspace shows the LLMS.txt upload field, upload llms.txt there and republish. If it doesn't, Webflow cannot host files at the domain root: host the file elsewhere (e.g. your own storage or a static host) and add a 301 redirect from /llms.txt to that URL in Site settings > Publishing > 301 redirects.
3.Structured data: paste the content of json-ld.html into Site settings > Custom code > Head code (site-wide custom code requires a paid Site plan). For a single page, use Page settings > Custom code > Inside <head> tag instead.
4.Meta: in the Designer open Pages, click the gear icon next to the homepage and fill in the Title tag and Meta description under SEO settings using the texts in meta-suggestions.html.
5.Publish the site and re-scan the domain on AIVIS.

Download the bundle from your AIVIS report first, then re-scan the site to check the score went up.