Congratulations on your new QuickBooks for Mac 2019, ejinayoshi.
I'm here to guide you in changing the check style to a voucher in QuickBooks for Mac 2019.
Please follow the steps I've laid out below:
5. Close the Preferences pane.
Once done, please try printing a check.
You can check out the QuickBooks for Mac 2019 User's Guide for the detailed steps. Just press Command and F, then enter "Voucher" to locate the Check Preferences section.
That should do it. If there's anything else I can do for you, please don't hesitate to leave a comment below. I'll get back here as soon as I can to help you again.