[tpm2] Re: Help - how to store a certificate in the NV under the platform hierarchy?

I tried:
tpm2_nvdefine 0x01C90000 -C p -s $DER_SIZE -a "ppread|ppwrite|platformcreate"

but i get the same error:
WARNING:esys:src/tss2-esys/api/Esys_NV_DefineSpace.c:344:Esys_NV_DefineSpace_Finish() Received TPM Error
ERROR:esys:src/tss2-esys/api/Esys_NV_DefineSpace.c:122:Esys_NV_DefineSpace() Esys Finish ErrorCode (0x000009a2)
ERROR: Failed to define NV area at index 0x1C90000
ERROR: Esys_NV_DefineSpace(0x9A2) - tpm:session(1):authorization failure without DA implications
ERROR: Failed to create NV index 0x1c90000.
ERROR: Unable to run tpm2_nvdefine

Thanks anyway for your help and clarifications!