It is reported totally on the 2019 tax return. There are various worksheets out there, as Google will show you https://www.google.com/search?q=1031+exchange

I prefer to spend a couple of bucks on Tax Tools It has a super 1031 worksheet that leads you to doing the PS input to get the forms right. In addition it has many other tools, including a simple tax planner, flow charts to help you with not so obvious how to file and can I claim that kid questions, and more! They have excellent support. I bet if you bought it now, you could get next year free.