What are all the settings you have programmed into the controller with the setup software?
How exactly is the system wired, with what specific parts? (a complete list of everything in the system may be helpful to figure out the problem(s); links to where they were purchased if from online stores may help us see information that could lead to solutions)
Where is the beep coming from, exactly, and what exactly is happening / are you doing that causes the beep?
What does the manual of the device doing the beeping say the beep code it is giving you means?
If you have to post screenshots of the various setup software pages, you can simply copy and paste them right into your post. On a Windows PC, just hold the Alt key and press the PrtSc key to take a screenshot of just the program you're in at the moment (like the setup software), then hold Alt and press Tab to switch to your browser and then paste (ctrl-V) into the box you type into.
The more accurate and complete the information you provide, the less we have to guess, and the more likely we can provide help that will lead to a solution.
Note that if you need more power than you had before, you will almost certainly need a bigger / more capable battery as well, since normally the batteries used with systems can only (barely) power those systems at their factory-setup limits. Even just modifying settings for higher power demand on the factory system can cause it to no longer work correctly with the existing battery, causing cutouts or shutdowns.
Changing to a much higher power-demand system usually means replacing the battery as well, with one capable of handling the needs of that system under the specific conditions you're using it under.
If you're still using the original battery, you are almost certainly still limited in power to whatever it could output to the original system as it was originally setup.
According to this site
The newest member of our award-winning eMTB range, the Vitus E-Mythique LT is a riot on the descent and a magic carpet on the climb. Powered by our own custom tuned Bafang M510 motor system developed in partnership with Bafang, it blends the ethos of our award-winning Mythique trail bike with...
vitusbikes.com
that's only a 250w system, with a 650wh-capacity battery,
- Smooth Bafang M510 motor produces 250W max power and 95Nm torque
- Long range 630Wh internal battery
but your new controller
ND72360 2000-3000W 72V EV Progammable FOC Controller Fardriver Brand For Electric Scooter. Electric Bicycle
www.far-driver.com
is capable of drawing about ten times what the battery is designed to handle, so the battery probably won't survive very long if it works at all under load.
If you haven't already done so, you may also wish to verify that the parts you have (or intend to get) can handle the power needs by using the various calculators or simulators on the internet, such as those from ebikes.ca , to guesstimate how much power it takes to do the specific job you need your bike to do for you under your specific riding conditions.
You may also find this thread useful
These start to turn up here and there on the forum. It seems like they were only available in China before, but now they seem to be available on more places. Like qs motors...
endless-sphere.com
(BTW, using all caps doesn't get you more attention, it just makes it harder to read what you type. Using normal sentences, punctuation, etc. will make it easier for us to read, and thus easier to help you).