How to develop a Image template editor, that can be used to create templates with text/images and generate images

I want to develop a Image template editor and embed into web app, that can be used to create templates with text/images and generate images dynamically based on your inputs. There are many saas providers apitemplates.io placid.app usestencil.com but are expensive to integrate their white label editor.Web app is developed in react and able to embed drag and drop image editors, but not that can create template and generate images later. Any inputs on how to develop this create custom templates and generate images?

I could not find any inputs on web.