As far as I know, Pages v11.1 on Big Sur now only supports its own equation editor input as Wiris will not be delivering MathType for macOS Big Sur. I know of no other Math tools that are integrated with Pages, other than its own equation editor which requires knowledge of LaTeX or MathML.
You can search on the Internet for Equation generator online, and will likely find sites that may use ideograms for math functionality that allows you to build the equation with point and click, or many others that expect you to know sufficient LaTeX or MathML to achieve the same end. In either case, you will be able to download the equation as PDF, or an image that can be dropped on Pages.
Or you use Word on MS Windows with a Wiris MathType 7 subscription to generate equations in Word.
Or if you are on an Intel Mac that supports Mojave, you can roll back to Mojave from that last Time Machine backup, and use MathType 6.7H with Pages v10.1 — if you have those versions.