Most framework like React Native and Ionic allows you to built on their server. Meaning that they can help you compile and provide you with and .ipa file.
The problem is you need Xcode or Application loader to submit your app to Apple App Store Connect. Both of these are only available on OSX. To overcome this solution you have 2 options that I am aware of
- Rent mac virtually. http://www.macincloud.com
- Use website that helps you to upload your app (You need to have .ipa file). http://www.connectuploader.com
