Call ext. variable in a cell (zoho sheet), passed in url

Call ext. variable in a cell (zoho sheet), passed in url

public.sheet.zoho.com/public/dllorens/test?varTest=Dan

I want to pass the sheet a variable in the URL. for example, in the one above, I want to pass it the variable "varTest" and have the value = "Dan"

I want to call this variable from a cell on the page and have it display "Dan" in the cell. Please tell me how to do this, I've been reading forms for an hour and I feel like an idiot