How to set `contextType` on stateless component

There is no way of doing it with contextType.
You should use contextConsumer with renderProps pattern or React's useContext hook (introduced in React 16.8)

The first one will look like this:

const MyClass = (props) => {
    return (
        <myContext.Consumer>
            {({name}) => <View>{name}</View>}
        </myContext.Consumer>
    )
}

And the second (preferred) way of doing it looks like this:

import React, {useContext} from 'react';

const MyClass = (props) => {
    const {name} = useContext(myContext)
    return <View>{name}</View>
}