I did it like below:
async find(ctx) {
const response: any = await strapi.service('api::hero.hero').find({
populate: ['image']
});
const hero = [{
'id': response.id,
'title': response.title,
'image-default': response.image.url,
'image-large': response.image.formats.large.url,
'image-small': response.image.formats.small.url,
'image-medium': response.image.formats.medium.url,
'image-thumbnail': response.image.formats.thumbnail.url
}];
return hero;
},