For a Wix site. Nothing to install, no plugin and no script: you paste a link. First connect your shop at /integrator/connect (or with your agent: /integrator/agent-guide) and note your <slug>.
https://apibase.pro/m/<slug>/p/<sku>https://apibase.pro/m/<slug>/cart?items=<sku>:1https://apibase.pro/m/<slug>Use the link text "Buy with your AI agent". Ready-made markup for each: /integrator#options.
Menu names change between versions of the builder; the link itself does not. Check the result at /integrator/check/<slug>.