Not sure how to set the text fields though

Went ahead and did it myself to give you an example :)

imgflip.com/memetemplate/296743666/Marjorie-Taylor-Greene-Hotline-Bling

Make the changes you want on your template and then hit this button

Be sure when you create the new template you check this box and give it a title

Looks like you did though!

Thanks: that text box settings one was the secret sauce!