how about your search little in docs and forum. you need to edit your middleware in config folder.
module.exports = [
'strapi::errors',
{
name: 'strapi::security',
config: {
contentSecurityPolicy: {
useDefaults: true,
directives: {
'connect-src': ["'self'", 'https:'],
'img-src': ["'self'", 'data:', 'blob:', 'your-s3-bucket-url.com'],
'media-src': ["'self'", 'data:', 'blob:', 'your-s3-bucket-url.com'],
upgradeInsecureRequests: null,
},
},
},
},
'strapi::cors',
'strapi::poweredBy',
'strapi::logger',
'strapi::query',
'strapi::body',
'strapi::favicon',
'strapi::public',
];