javascript – Migrate the current JS React project to run in Sharepoint

Our team created a React SPA based on js and not ts. From what I've seen, creating and using a web part requires typed text. This project is quite large and I wonder what would be our best option to integrate this spa Sharepoint. Is the conversion of the project to typed text the best option? Are there any other options for deploying a SPA in Sharepoint without creating a Webpart?

In addition, we would like to have a stand-alone test site, apart from Sharepoint. Would we essentially need 2 different code bases to do it?