Pass data to Dropdown list? or change default selection it the list?

I have forms through my site that are just “Enter Your Name” and “Select Your Service”. Whenever you use any of them and click submit, they take you to the larger “Request Appointment” form, which automatically has the Name filled out. I’m passing the name and selected service to the larger form via the url (site.com/?name=your-name?service=your-service.

This works great for the standard text field “Your Name”, but unfortunately I haven’t found a way to pass the drop-down selection from the smaller form to the larger form.

Anyone have any suggestions to make this work?

I found this link that appears to do exactly that, but its quite old and im not following how to accomplish this.
https://trackitweb.com/contact-form-7-set-the-default-value-for-select-fields-using-the-url/