That, to me, is an oversight of the marketing team not updating the website from the previous year. This question had been before and Intuit confirmed each time to the users that it's not possible - unless, of course, something has changed. FWIW, here's the article about eSignature and its limitations:
It should work, but there's an issue blocking credits purchased in Calendar Year 2021 from being consumed in ProSeries Tax Year 2019 by normal means. We are working on a fix that I believe should go out within the next week.
If you have already requested an eSignature for the client before, you should be able to go into the Dashboard Widget and request Signatures from there without getting blocked.
The units purchased will need to be used by12/31. Any unused units will be lost. Your eSignature purchase is not refundable or transferable and may not be carried to another tax year. Therefore, do not purchase more than you need to use for this tax season.
If so, yes.. I think it should say this:
The units purchased will need to be used by12/31. Any unused units will be lost. Your eSignature purchase is not refundable or transferable and may not be carried to another tax calendar year. Therefore, do not purchase more than you need to use for this tax calendar year. Also note, you can use any eSignatures you purchase in prior versions that still support eFile.
The esignatures I purchased last week for 2020 are now showing up in the 2019 & 2020 eSignature Dashboard. I''ll be trying to submit a 2019 1040 on the 12th.