If the data is negative in BUSY but positive in the portal, then you need to reconcile the data. For this, you need to follow the below steps:
Step 1: Open the Administration menu and select Configuration.
Step 2: Choose Features or Options, then GST or VAT, and enter your GST portal username in the GST Portal User Name field and save it.
Step 3: Next, open the Transaction menu and select GST Misc Utilities.
Step 4: Choose Download GSTR JSON Data
Step 5: Then select Download GSTR1, GSTR2A, GSTR2B, or GSTR3B as required.
Step 6: Click on the download button along with the month, then verify with the OTP and download it.
Step 7: Now, under the GST Misc. Utilities, select the Reconcile GSTR Data option.
Step 8: Choose and reconcile GSTR1, GSTR2A, GSTR2B, or GSTR3B as per the requirements.
Step 9: Enter the period, and you can match your GST portal data with BUSY data.