How can we show a Submit button based on a condition?

can you also please help me with the submit button as this doesnt seem to be coming up - I have set it so that it comes up when a certain section is filled in, however it wont load

Upon checking the form you refer to, I can see that the field, which is involved to a conditional statement to show the Submit button, is hidden based on other conditions. 

Meanwhile, that field is already Required, so the form will not be submitted until that field is filled. 

My best recommendation would be to remove that condition at all.

Also I have noticed, that the Submit button is placed UNDER the "Sun & Tan" section, which is HIDDEN. Please set this section as visible, to get that button back to the form.