Generate a robots.txt that names the major AI crawlers and an llms.txt skeleton that points answer engines at your key pages. Defaults follow the rule of allowing named AI crawlers unless you have a reason to block them.
Place this at your site root as /robots.txt. The wildcard block sets site-wide rules, each named crawler is allowed explicitly, and the sitemap lines sit at the top.
Place this at your site root as /llms.txt. Replace the example links with your real pages and write each description specific to what that page answers.