We request that you create the expenses with the vendor and tax.
Kindly go to Expenses >> Click on Create Expenses >> Turn on the Create Expenses with Tax toggle button >> Enter vendor details >> Create Expense >> Click on Add Expense.
Once you create expenses with tax, expense will displayed in the GSTR-2B.
Please note: This is indicative and for reference only. The actual calculation of GSTR2B will be done automatically on your GST portal based on actual filings done by your vendors.