Iframe thank you page wont show.

When I add my iframe to my landing page, at the end of my form, when the user has finished submitting fields, my form will not show a landing page...

I have checked some of your forms and I can see you have properly set up your thank you page. Could you please provide us the form where you're getting this problem as well as the webpage where you have embedded it? 

Once we have the link to the webpage and form we will be able to submit your form as  a test and find why this may be happening, please also try re-embedding your form and let us know if that helps. 

I figured out the final button on thr form was a nxt button not a custom
button
...

I am glad to know that you were able to resolve the issue. I checked your most recent form https://www.jotform.com/63535820836157 and I see that it has a submit button at the end instead of a next button. When that button is clicked, it should now redirect your users to your custom Thank You page.

If you need further assistance, please do let us know.
Cheers.