Yes, all returns can be filed using BUSY. For this, you need to check the below steps:
Step 1: Go to the Display tab and click on GST Reports.
Step 2: Select GST Returns and choose the return options you want to generate, such as GSTR-1 eReturn, GSTR-3B eReturn, etc.
Step 3: Select Report to be generated options such as Direct Upload, JSON, CSV File, etc. (The direct upload option is currently available for GSTR-1 only.)
Step 4: Enter the period, and you can generate GST returns according to the option selected.