What is the correct method to record non-invoiced BB transactions like advance receipts in GSTR-?

Sure, here's a simplified step-by-step guide to recording advance receipts for non-invoiced B2B transactions in your GSTR-1: 
 Step 1: Enable Advance Receipt Tax 
 In your accounting software, find the Administration section. 
 Inside Administration, look for Configuration and then Features/Options. 
 Within the Features/Options, you should find an option related to GST/VAT. Enable the option that says tax on advance receipt. 
 After enabling this option, remember to click the Save button to save your changes. 
 Step 2: Record the Advance Receipt 
 Now, go to the Transaction section in your accounting software. 
 Select Receipt Voucher and choose to add a new voucher. 
 Fill in the necessary details, such as the voucher series, date, and specify that this is an Advance Receipt for the GST nature. 
 You'll also need to select the relevant accounts (debit and credit) and enter the amount. 
 Step 3: Save the Voucher and Allocate the Advance with GST 
 Click the Save button to save this voucher. 
 After saving, you may see a new window for allocating the advance with GST. 
 In this window, provide information such as a reference number, the amount of the advance, and the tax rate percentage. 
 Make sure to save this information, and then save the entire voucher.