CF7 Grid Extention Html disapears after saving

trying to create a Slider Form for our Carglass Workshop in Bavaria, Germany.

is the slider form working? I am not able to see it on your linked page.

I am posting screenshots, cause if I am writing it down in this mail, it would be marked as spam:

the screenshots are not accessible, you need to set the sharing options to ‘links visible to anyone’.

Ok, the slider form is working (I need to scroll down to the bottom of the page to see the prev/next buttons).

So the plugin is working fine!

The problem I am running into is, that I want to use some JavaScript to only alow one Checkbox within a group at the time.

this is a javascript question which is unrelated to this plugin. Please ask on a Javascript forum such as StackOverflow.

Now i wanted to add the name and onclick inside the html:

don’t create input fields within the HTML, use the CF7 field tags instead, else the CF7 plugin will not be able to validate/process/add to notification mails your submitted values. This is not the recommended way, you really need to understand what you are doing to design forms like this.

The onclick attribute is not allowed by the WordPress wp_kses_allowed_html post content sanitizer function by default. Again, you should be using JavaScript/JQuery to bind events on your fields rather than inserting oncliick attributes.

It seems like it doesn’t save.

indeed, not on the title element as it is dynamically created when the grid UI is loaded. However, it will work if you put it on the parent element,

<div class="container cf7sg-collapsible nichtsichtbar">
  <div class="cf7sg-collapsible-title"><span class="cf7sg-title">1. Glasschaden angeben</span></div>
  ...

you can then target the title

.nichtsichtbar > .cf7sg-collapsible-title{}

to dynamically control collapsible rows and slides, see the advanced section tutorials.

alternative is to use a scrolling window in your first slide, something you can achieve using CSS