Rebuild my angular 7 app. into a commercially ready angular 9 app

PWA.. Task manager for mechanical handling trade. I have built the concept in angular 7 and have a fully working prototype but now i require a rewrite now that we have figured out what we need and how [login to view URL] implement each aspect, and need to get it ready for commercial use. I use firebase as a backend and utilise cloud functions to distribute the uploaded information to the correct documents, I would welcome input from a professional developer on how to improve this app when rewriting. the app allows our engineers to fill out worksheets and get them signed digitally. our clients to access the worksheets as soon as they are signed in PDF form, as well as register / request call outs for breakdowns servicing and so on. companies that we work for as a contractor to list their clients, create task requests, view their clients PDF's create service reminders. Admin's. Our office staff can read write and update all aspects on the data, create tasks for our engineers, convert job requests to tasks, set servicing reminders, list all clients to create tasks. you will get the idea when you see the app in action... I use bitbucket as my git provider. timeframe for this to be ready for release would be 2-3 weeks tops If you require any other info please let me know..