tabletop.js "not supported"

I’m having problem using fetch() to retrieve rows from Google sheets. Saw article describing tabletop.js as a tool specifically for working with Google sheets, wanted to explore it in Wix, but was disappointed to see it as “not supported.” That seems to mean it cannot be requested.
Can someone give simple explanation (e.g., “the package has serious security holes” or whatever reason)? Is there another package similarly created to make working with Google sheets easier, which is available in Wix? (An article by Shahar Talmi suggests using axios as a higher level API than fetch–so perhaps easier for newbie like myself to apply? Or is there another specially targeted package like tabletop?)

Background: Working with googleapis, it appears that the get can only use a range filter, but I need content filter for selecting rows, so it seemed that fetch() with query parameter is my alternative. But I’m having problem with fetch() where get is “succeeding” (200 and status text of “ok”) but returning a null body, even though the resource URL returns a csv file with row values (when used directly from browser.) So that is prompting my interest in alternatives such as tabletop.js.

Thank you for any advice on this.