How to add an ms or handwritten signature to a pages document?

I don't know what you mean about "the glass". I took a picture of my signature with my phone and transferred the picture to my computer. I don't remember what program I used to make the background transparent. It's the sort of thing many image editing programs can do. A search for "make image background transparent" should turn up things. For example:

https://www.adobe.com/express/feature/image/transparent-background

I use a picture (.png format) of my signature with a transparent background. I can then insert it just like any other picture.

Tools>Annotate>Signature>Manage Signatures>Create Signature

Best of luck!

Oh, just remembered that Preview has a signature option that lets you write your signature on a trackpad as I recall. You might want to look into that as well.