Make sure your form fields names are the same as your mailwizz subscription form fields, and then simply point out your form to submit the data to your mailwizz subscription form, just like we do on https://www.mailwizz.com/
@segunoloye, I could not make it work with Elementor, can you tell me where did you add the form link in Elementor. Did you use Elementor form widget and then add link to to a field on that widget or how? thank you in advance.
In the section you want to paste the form code. At the top of the form field, insert a text widget. Then under that where you will paste the form code drag an HTML widget and paste your code in it. That's all. . See these screenshots: https://segunoloye.tinytake.com/tt/NTQ2MTAwM18xNzA3NTAxMw. I attach a screenshot for you as well.