Well,

it turns out that this is the correct forum.
So I have an Eggbot Board from JJROBOTS VBersion 1
There is nothing installed so far.
If I plug in the USB port. the blue LED on the ESP is flashing one time.
I have found out that there is that EBBUpgraderGUI_v270 Software.
I cannot connect to the board.
Errormessage is saying:

Building a list of COM ports …
Found the following ports:

COM5
Testing port … no EBB found
Testing port COM5 … no EBB found
Click Exit (or click Start Upgrade again to update more EBBs)

There is no other program running which is occupying the USB port.
Do I need to equip the board with the driver Hardware first?