lpc4370 for keil5 load error: Erase Failed!

It looks like you are using this device:
    www.keil.com/.../

That page shows there is a "Dual Core CM4 Blinky" example. If your board has a similar layout to this our board, then you could use it too.
    https://www.keil.com/mcb4300/

Open the Pack installer, C:\Keil_v5\uv4\PackInstaller.exe

- On the top left of the window, for "Search", type "lpc4370" - the list below gets filtered.
- Select the device (entry with a green icon) from the list below – on the right side of the dialog updates with Software Packs relevant to this device.
- For the "Packs" tab, install the NXP:lpc4300_DFP pack (if necessary).
- On the top right of the screen, select the yellow "Examples" tab.
- On the "Dual Core CM4 Blinky (MCB4300)" row, click the "copy" button - a dialog pops up.
- Pick a directory, click both the check boxes, and press OK - a new Keil µVision session opens with the example.
- Build the project, Connect a USB cable to the board and start the debugger.

It looks like you are using this device:
    www.keil.com/.../

That page shows there is a "Dual Core CM4 Blinky" example. If your board has a similar layout to this our board, then you could use it too.
    https://www.keil.com/mcb4300/

Open the Pack installer, C:\Keil_v5\uv4\PackInstaller.exe

- On the top left of the window, for "Search", type "lpc4370" - the list below gets filtered.
- Select the device (entry with a green icon) from the list below – on the right side of the dialog updates with Software Packs relevant to this device.
- For the "Packs" tab, install the NXP:lpc4300_DFP pack (if necessary).
- On the top right of the screen, select the yellow "Examples" tab.
- On the "Dual Core CM4 Blinky (MCB4300)" row, click the "copy" button - a dialog pops up.
- Pick a directory, click both the check boxes, and press OK - a new Keil µVision session opens with the example.
- Build the project, Connect a USB cable to the board and start the debugger.