How to get geometry.vertices?

code as follow:

const geometry = new THREE.CircleBufferGeometry(10, 64);

but receive an error that geometry.vertices is undefined when running,so how can I fix it?

If you want points in formation of circle, then use this one-liner:
let pts = new THREE.Path().absarc(0, 0, 10, 0, Math.PI * 2).getPoints(64);;

Since r125, all standard/primitive geometries are buffer geometries, so there is no .vertices property, as they store vertex data in .attribute.position buffer attribute.