Its element type 'ReactElement<any, any> | Component<IIframe, any, any> | null' is not a valid JSX element.

[HT-Moh]

Type issue, maybe due to the ReactNode' on React 18

"react-iframe": "^1.8.0"
"react": "^18.0.0",next``

Maybe related:

DefinitelyTyped/DefinitelyTyped#46691
DefinitelyTyped/DefinitelyTyped#56210

[eps1lon]

Explanation and workaround can be found in software-mansion/react-native-svg#1741

[HT-Moh]

The following solution worked for me:
Update packages react and react-dom and types

 "react": "^18.0.0",
 "react-dom": "^18.0.0",
 @types/react": "^18.0.4",
 @types/react-dom": "^18.0.0"

Add the following to package.json

"resolutions": {
    "react-i18next": ">=11.16.4"
  }