how to combine sentences in several straight column cells based on dates in excel [closed]

Consider the picture below. I have a list of transactions, and details of each transaction span several rows (see third column). Date is populated only on the first row of transaction, so if Date is empty, it means that this row belongs to the same transaction. What I'm trying to achieve is to concatenate all transaction details for each transaction and store them in one cell, like shown in the Alias column for the first two transactions.