Combination of daily receipts and sales invoices

I already know that you cannot fill in both daily receipts and sales invoices for the same income. It is one of the two. But you can combine them in your accounts if they relate to different types of income. For example, can you enter a few invoices for customers who wanted them on one day and for other day enter the income only as daily receipts, because these customers did not want an invoice?

I cannot find a similar question and have not read about this in the learning environment, but I am probably not the first to ask this question, right?

Thank you in advance.