I was reading the docs to implement Firebase Crashlytics in my project and it says this

Step 4: Build your project and upload symbols

iOS+ (Apple platform)
From the Build Settings dialog, export your project to an Xcode workspace.
Build your app.
For Apple platforms, the Firebase Unity Editor plugin automatically configures your Xcode project to generate and upload a Crashlytics-compatible symbol file to Firebase servers for each build.

https://firebase.google.com/docs/crashlytics/get-started?hl=en&authuser=0&_gl=1*1mno2w4*_ga*OTE2NjIzNTg2LjE3MDAwNDE0MDk.*_ga_CW55HF8NVT*MTcwMTA5Njc1Ny40LjEuMTcwMTA5Njc4My4zNC4wLjA.&platform=unity#build-project-upload-symbols

How would this be resolved in the iOS builder considering that Xcode is not in our equation.