No, your parameter name needs to be the name you set for the parameter - nothing to do with an input on your current page.
If you’re trying to set the initial content to the value of another input on the same page then there’s no need to use parameters for this.
Just set the initial content of whatever input you want to set to be the value of the other input (although I’m not sure what the purpose of that would be).
My assumption was you want to send the value from one page to another (perhaps I misunderstood what you’re trying to do).
But if that is the case, and you want to get data from the URL, then you don’t need to get the data from an input on the current page as well.
You send the data from the input (on the previous page) to the new page (in a URL parameter).
Then read that data on the new page from the URL parameter.
So, on your first page you send the parameter (using the ‘send more parameters to the page’ option on the ‘go to page’ action - or by adding ‘?’ then the parameter name and value, if using a link, eg.
Name the parameter (key), for example ‘amount’ and set the value to the input’s value:
Then on your second page, in the initial content you want to set, use Get Data From URL, and specify the name of the parameter you want to get (amount), and the type of content it is (number).