Please help i don't understand what the client meant " No tracker is allowed because there is sensitive information. You can add time manually". and this: Manual "time not allowed - Request"
The time tracker is what Upwork uses to track time worked on a project it also ensures you will hopefully have some very limited protection (IF you use it exactly as described by upwork in the ToS - so that means making very detailed memos about what you are doing for each time period, working soley on the project with enough activity)
On the other hand, you can just add hours manually but this has no protection but doesnt require use of the tracker (wich takes screenshots)
In either case - I would be very careful moving forward. There are lots of scams on Upwork at the moment, and that does not sound like a normal reasonable request to me.
Have you signed an NDA to work on this project? if not then that sounds even more fishy if things are so sensitive.
I have worked on several project WITH NDA's but never been asked not to use the time tracker.
If they turn off manual time, then they are tricking you into getting paid when they want you to. Use tracker. They turned off manual time so you have no way to bill except through tracker. If they don't want you to use tracker, they can pay you upfront.