Yes, you can create GST-compliant invoices on Open. If your business has registered a GSTIN, then you can share GST-compliant invoices with your customers.
You can update the GSTIN while creating an invoice. The option to update the same is available on the right side of the invoice or You can go to the Setting section from the top right corner and then click on ‘Settings’ and then click on ‘ Company’. Once done Go to ‘Tax & Compliance’ and add GSTIN by clicking on edit details.