How to add Booking Calendar in Gutenberg editor in Classic (old) way?

1. Click on "+" Plus button to add new block.
2. Select Formatting section and click on "Classic" block, or simply enter "Classic" in Search field. New "Classic" block will be added to the page.
3. Click on "Booking Calendar" icon in "Classic" toolbar.
4. Configure Booking Calendar parameters in popup dialog and click Insert button. Publish / Save the page.