upload_image_expo.js

const pickImage = async () => {
	let result = await ImagePicker.launchCameraAsync({
		mediaTypes: ImagePicker.MediaTypeOptions.Images,
			allowsEditing: true,
			aspect: [1, 1],
			quality: 1,
			base64: true
		})
	if (!result.cancelled){
		// I'm adding the data:image, if you want to use the image locally before uploading, you can use a state hook first
		uploadImage('data:image/png;base64,' + result.base64)
	}
}
  
const uploadImage = async data_url => {
	let upload = functions.httpsCallable('uploadExpoImage')
	let res = await upload({
		data_url: data_url,
		path: `alejov/images` //Replace with the location where you want your image
	})
	if (typeof res.data === 'string') url = res.data
	// Now you have url that is whatever you returned from uploadExpoImage
}