For tax year 2019 there is NO requirement to purchase any 2019 online edition, nor is there a requirement that you must file a 2019 tax return using the online editions before you can access to a prior year online return.
You only need to register the 2019 online account to access the prior year online tax returns.
See this TurboTax support FAQ for accessing prior year online tax returns - https://ttlc.intuit.com/community/prior-year-return/help/how-do-i-access-my-prior-year-return/01/270...
