The e-invoice is not getting generated for the credit note I created. It shows the original invoice instead. What should I do to generate the e-invoice for the credit note properly?

If the e-invoice is not getting generated for the credit note that you created, you need to follow the below steps:
Step 1: To generate an e-invoice for the credit note in BUSY, ensure that e-invoice configuration is done in GST or VAT from Administrator, then Configuration, then Features or Option.
Step 2: Also, make sure that your QR code print option is enabled in the Sales invoice bill print option, as well as Print E-invoice IRN, Ack. No., Act Date & QR code from Administration, then Configuration, then Invoice / Document Printing, then find your Sales Invoice, whether it is Standard or Advance. If it is Standard, select the sales invoice and enable the option, or if it is Advance, design in advance format.
Step 3: Also, make sure the Voucher Series Configuration option generates an e-invoice after the saving option is enabled.
Step 3: After confirming the above option, you need to go to the particular credit note bill, and in that, you will get the E-invoice details window. In the e-invoice details, specify the e-invoice required, yes, then click OK.
Step 4: After saving the credit note, you will get a dialogue box asking, Do you want to generate an e-invoice? Click Yes. After that, select Automatic Option, and then you will find the Automatic E-Invoice INR Generation Window. In that window, select relevant option Yes if required, or either skip by No.
Step 5: After that, click on the OK option. You will get the check possible error option. Click on the check possible error option in this window. If you have any invalid transaction details, it will show you in red. You need to correct that invalid data by clicking on the red entry.
Step 6: After checking for possible errors, you need to go to the Generate and Viwe E-Invoice option, where you will get a summary of the credit note E-invoice, check the details, and then click on the Generate E-Invoice option. Your credit note will be generated for an e-invoice.
Step 7: After generation on the e-invoice, you will find the option to print the e-invoice. Click Yes 
Step 8: After that, your e-invoice will be printed successfully, and in the credit note bill print format, you will find a QR code and an e-invoice ID, Ack. No., and Act Date.
By following the above steps, you will be able to generate your e-invoice for a credit note.