After a bad manipulation i have unfortunately deleted the bootloader of my arduino nano 33 BLE (nRF52840).
I saw that it was possible to reburn the bootloader with another arduino using the ICSP pins of the target arduino, but I did not find how to do it on the nano 33 BLE.
thanks for your answer, any help will be welcome.
P.S.: I have at my disposal an arduino UNO, an arduino DUE and another 33 BLE.