Fix accessibility issues

Open the Props tab and expand Page settings → Accessibility & validation. Problems are listed errors first; each starts with the element it concerns, such as <img>#hero.
Select that element on the canvas. Checks → Element checks now shows only its problems.
Fix it using the table below. The problem disappears from the list once fixed.

Message	Fix
Missing alt text	Images & media → Image → alt: describe the image. For a purely decorative image, click decorative instead (sets `alt=""`).
This form control has no label	Select the field’s label and set Label → for to the field, or set aria-label on the field.
This link/button has no text or label	Add text inside it, or set aria-label.
Give the iframe a title	Embeds → Iframe → title.
The id ”…” is used by N elements	Give one of the elements a different id in ID & class.
… points to missing id …	Pick an existing element in that attribute’s picker, or remove the attribute.
Heading level skipped	Change the heading so levels go down one at a time (h2 → h3).
The page has no language	Page settings → Language → lang.
The page has no `<title>`	Page settings → Title & description → Title.

Troubleshooting

A structural error such as “<li> should be inside <ul>”. Move the element into the right parent on the canvas; attributes can’t fix it.