You can use the upgrade option to choose Plus.
How do I upgrade or switch to a higher version of TurboTax Online?
https://ttlc.intuit.com/community/upgrading/help/how-do-i-upgrade-or-switch-to-a-higher-version-of-turbotax-online/00/26239
Why don't I see the Upgrade option in TurboTax Online?
https://ttlc.intuit.com/community/upgrading/help/why-don-t-i-see-the-upgrade-option-in-turbotax-online/00/25535