To remove the button from all slides, either change the “Slider content” setting to “Full content” in Customizer > Franz Josef: General > Slider, or add the following code to Customizer > Additional CSS:
.slider .call-to-action {
display: none;
}
To remove the button only on specific slides, use the following code instead:
#slide-9 .call-to-action {
display: none;
}
The number after #slide-
is the post ID of the slide that you want to remove the button from.