web3 cli - Error deploying contract: invalid private key: invalid length, need 256 bits

[BrwGamer]

I'm following this tutorial: https://medium.com/gochain/how-to-create-and-deploy-an-nft-smart-contract-in-10-minutes-e0d7ef8e59fc

When running sudo web3 contract deploy MYTEST.bin

This error happens:

ERROR: Error deploying contract: invalid private key: invalid length, need 256 bits

I already tried by setting the private key without the 0x in front of it but the error is the same.

How to make it works?

Thanks

[BrwGamer]

see the discussion for more info