Wix has gone further than most builders on this, and you probably have more of it done than you think. There are four things worth checking, and two of them Wix may have handled for you already.
1. Let the crawlers in
Wix gives you a real robots.txt editor in the dashboard, which several hosted builders do not. It is under SEO and GEO rather than in the editor, which is why people miss it. Where to find it.
2. Add structured data
The custom code panel takes it site-wide, and the one thing that catches people is publishing: custom code does not appear on the live site until you do. The steps.
3. Check your llms.txt
Wix generates one for you and keeps it current, which puts you ahead on this check without having done anything. Worth opening once to read what it says about your business, and worth knowing that editing it stops the automatic updates. What that trade-off means.
4. Rewrite your opening lines
The one no platform can do for you, and the one that moves a score furthest. How to write a page an engine can quote.
Then your titles, summaries and headings
Each page’s SEO panel holds its title and summary, and each heading and photo has its own setting. Where they are on Wix.
What Wix cannot do
You cannot rewrite the underlying markup of a page, so anything that depends on hand-editing HTML is out. In practice this costs you very little here: structured data goes in as its own block, the viewport tag is handled for you, and the contact details go in a footer text element rather than as pasted markup.
The one thing genuinely outside your reach is the infrastructure. If the finding says a crawler was turned away by a firewall rather than by robots.txt, that is Wix rather than you, and their support is the only route.