The error: The field Bal. Account No. of table Gen. Journal Line contains a value (10100) that cannot be found in the related table (G/L Account). Page Edit - Cash Receipt Journals has to close.

How I got there:
Walkthrough: Setting Up and Invoicing Sales Prepayments (https://docs.microsoft.com/en-us/dynamics365/business-central/walkthrough-setting-up-and-invoicing-sales-prepayments)
To this point:
To apply a payment to the prepayment invoices
- Choose the Lightbulb that opens the Tell Me feature icon, enter Cash Receipt Journals, and then choose the related link.
- Fill in a journal line with the following information.
The error occurs immediately after step 1, so there is not an opportunity to enter the values per the example:
| Field name |
Enter |
| Document Type |
Payment |
| Account Type |
Customer |
| Account No. |
20000 |
Any advice is appreciated.