Cannot install Payment Form in a Joomla! release prior to 4.4.0?

I'm running into an issue installing version 7.3.0 of Payment Form.

WarningCannot install Payment Form in a Joomla! release prior to 4.4.0
Extension Update: Custom install routine failure.
Package Update: There was an error installing an extension: com_pmform.zip

Running Joomla! 3.10.12 Stable. (Yes, I know this is old as hell, and no I'm not in a position to upgrade it yet). Any thoughts about what I'm doing wrong?
Thanks in advance!

Hi

The latest version of Payment Form is only compatible with Joomla 4/Joomla 5. If you use Joomla 3, please submit a support ticket so that we can send you older version of the extension which is Joomla 3 compatible

Regards,

Tuan