Can I post a journal entry to Accounts Receivable without specifying a customer name?
AR is always By Name. The point of AR = This Company or Person owes me. And you don't use JE. You want to use Invoice = unpaid sale. That is AR.
AR is one type of asset. Perhaps you are asking about AR, but what you really need is a Loan or Other type of Asset = owed to you, not from Sales to customers. Employee Loan, for instance, or Shareholder Loan. Not AR. Not Sales.