Make a note of the naming conventions that should be followed while creating the blob container:
At the time of writing, this is the error message that the portal throws if you don't adhere the naming rules: This name may only contain lowercase letters, numbers, and hyphens, and must begin with a letter or a number. Each hyphen must be preceded and followed by a non-hyphen character. The name must also be between 3 and 63 characters long.