Your question is far too vague, and expects someone to take the time to first, figure out what the indicated model is, then to write complete code for that model, after making up some data it might fit to give you an example.
If you really want help, make some effort. Offer some data that would be validly fit by that model (whatever it is, I won't bother doing the research for you.) Show either the model as an expresion or provide a link or some documentation that describes it. If you want help, then why would yo make it far more difficult to get help? You might even make a serious effort, and try using a tool like the curve fitting toolbox. That would most likely find a quick answer to help you when you get stuck.
