How to have solid Awesome icon in React app?

I would add solid instead of regular one. I try this:

import { FontAwesomeIcon } from '@fortawesome/react-fontawesome'
import { faXmark } from '@fortawesome/free-solid-svg-icons'

<FontAwesomeIcon
    icon={['fas', 'xmark']}
    className={styles.popupClose}
    onClick={() => {
        props.completion()
    }}
/>

the regular style works:

<FontAwesomeIcon
    icon={faXmark}
    className={styles.popupClose}
    onClick={() => {
        props.completion()
    }}
/>

having those dependencies:

"@fortawesome/fontawesome-common-types": "^6.1.1",
"@fortawesome/fontawesome-svg-core": "^6.1.1",
"@fortawesome/free-solid-svg-icons": "^6.1.1",
"@fortawesome/react-fontawesome": "^0.1.18",